Prepared by R.R. Donnelley Financial -- Form of Underwriting Agreement

Hemosense, Inc., a Delaware corporation (the “Company”) proposes, subject to the terms and conditions contained herein, to sell to the several underwriters named on Schedule I to this Agreement (the “Underwriters”), for whom Lazard Capital Markets LLC, W.R. Hambrecht + Co., LLC and Roth Capital Partners, LLC are acting as representatives (the “Representatives”), an aggregate of [ ] shares (the “Firm Shares”) of the Company’s common stock, $.001 par value per share (the “Common Stock”). The respective amounts of the Firm Shares to be purchased by each of the several Underwriters are set forth opposite their names on Schedule I hereto. In addition, the Company proposes to grant to the Underwriters an option to purchase up to an additional [ ] shares (the “Option Shares”) of Common Stock from the Company for the purpose of covering over-allotments in connection with the sale of the Firm Shares. The Firm Shares and the Option Shares are herein, collectively, called the “Shares.”

The Company has prepared and filed in conformity with the requirements of the Securities Act of 1933, as amended (the “Securities Act”), and the published rules and regulations thereunder (the “Rules”) adopted by the Securities and Exchange Commission (the “Commission”) a Registration Statement (as hereinafter defined) on Form S-1 (No. 333-123705), including a preliminary prospectus relating to the Shares, and such amendments thereof as may have been required to the date of this Agreement. Copies of such Registration Statement (including all amendments thereof) and of the related Preliminary Prospectus (as hereinafter defined) have heretofore been delivered by the Company to you. The term “Preliminary

Prospectus” means any preliminary prospectus included at any time as a part of the Registration Statement or filed with the Commission by the Company pursuant to Rule 424(a) of the Rules. The term “Registration Statement” as used in this Agreement means the initial registration statement (including all exhibits and financial schedules), as amended at the time and on the date it becomes effective (the “Effective Date”), including the information (if any) contained in the form of final prospectus filed with the Commission pursuant to Rule 424(b) of the Rules and deemed to be part thereof at the time of effectiveness pursuant to Rule 430A of the Rules. If the Company has filed an abbreviated registration statement to register additional Shares pursuant to Rule 462(b) under the Rules (the “462(b) Registration Statement”), then any reference herein to the Registration Statement shall also be deemed to include such 462(b) Registration Statement. The term “Prospectus” as used in this Agreement means the prospectus in the form included in the Registration Statement at the time of effectiveness or, if Rule 430A of the Rules is relied on, the term Prospectus shall also include the final prospectus filed with the Commission pursuant to Rule 424(b) of the Rules.

The Company understands that the Underwriters propose to make a public offering of the Shares, as set forth in and pursuant to the Prospectus, as soon after the Effective Date and the date of this Agreement as the Representatives deem advisable. The Company hereby confirms that the Underwriters and dealers have been authorized to distribute or cause to be distributed each Preliminary Prospectus and are authorized to distribute the Prospectus (as from time to time amended or supplemented if the Company furnishes amendments or supplements thereto to the Underwriters).

1. Sale, Purchase, Delivery and Payment for the Shares. On the basis of the representations, warranties and agreements contained in, and subject to the terms and conditions of, this Agreement:

(a) The Company agrees to issue and sell to each of the Underwriters, and each of the Underwriters agrees, severally and not jointly, to purchase from the Company, at a purchase price of $[ ] per share (the “Initial Price”), the number of Firm Shares set forth opposite the name of such Underwriter under the column “Number of Firm Shares to be Purchased” on Schedule I to this Agreement, subject to adjustment in accordance with Section 8 hereof.

(b) The Company hereby grants to the several Underwriters an option to purchase, severally and not jointly, all or any part of the Option Shares at the Initial Price. The number of Option Shares to be purchased by each Underwriter shall be the same percentage (adjusted by the Representatives to eliminate fractions) of the total number of Option Shares to be purchased by the Underwriters as such Underwriter is purchasing of the Firm Shares. Such option may be exercised only to cover over-allotments in the sales of the Firm Shares by the Underwriters and may be exercised in whole or in part at any time on or before 12:00 noon, New

York City time, on the business day before the Firm Shares Closing Date (as defined below), and from time to time thereafter within 30 days after the date of this Agreement, in each case upon written, facsimile or electronic notice, by the Representatives to the Company no later than 12:00 noon, New York City time, on the business day before the Firm Shares Closing Date or at least two business days before the Option Shares Closing Date (as defined below), as the case may be, setting forth the number of Option Shares to be purchased and the time and date (if other than the Firm Shares Closing Date) of such purchase.

(c) Payment of the purchase price for, and delivery of certificates for, the Firm Shares shall be made at the offices of Lazard Capital Markets LLC, 30 Rockefeller Center, New York, NY 10020 at 10:00 a.m., New York time, on the third business day following the date of this Agreement or at such time on such other date, not later than ten (10) business days after the date of this Agreement, as shall be agreed upon by the Company and the Representatives (such time and date of delivery and payment are called the “Firm Shares Closing Date”). In addition, in the event that any or all of the Option Shares are purchased by the Underwriters, payment of the purchase price, and delivery of the certificates, for such Option Shares shall be made at the above-mentioned offices, or at such other place as shall be agreed upon by the Representatives and the Company, on each date of delivery as specified in the notice from the Representatives to the Company (such time and date of delivery and payment are called the “Option Shares Closing Date”). The Firm Shares Closing Date and any Option Shares Closing Date are called, individually, a “Closing Date” and, together, the “Closing Dates.”

(d) Payment for the Shares shall be made to the Company by wire transfer of immediately available funds to a bank account specified by the Company against delivery of the respective certificates to the Representatives for the respective accounts of the Underwriters for the Shares to be purchased by them.

(e) Certificates evidencing the Shares shall be registered in such names and shall be in such denominations as the Representatives shall request at least two full business days before the Firm Shares Closing Date or, in the case of Option Shares, on the day of notice of exercise of the option as described in Section 1(b) and shall be delivered by or on

behalf of the Company to the Representatives by credit through full fast transfer to the accounts at The Depository Trust Company (“DTC”) designated by the Representatives. Upon request, the Company will cause the certificates representing the Shares to be made available for checking and packaging, at such place as is designated by the Representatives, on the full business day before the Firm Shares Closing Date (or the Option Shares Closing Date in the case of the Option Shares).

2. Representations and Warranties of the Company. The Company represents and warrants to each Underwriter as of the date hereof, as of the Firm Shares Closing Date and as of each Option Shares Closing Date (if any), as follows:

(a) On the Effective Date, the Registration Statement complied, and on the date of the Prospectus, the date any post-effective amendment to the Registration Statement becomes effective, the date any supplement or amendment to the Prospectus is filed with the Commission and each Closing Date, the Registration Statement and the Prospectus (and any amendment thereof or supplement thereto) will comply, in all material respects, with the requirements of the Securities Act and the Rules and the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations of the Commission thereunder. The Registration Statement did not, as of the Effective Date, contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein not misleading; and on the Effective Date and the other dates referred to above neither the Registration Statement nor the Prospectus, nor any amendment thereof or supplement thereto, will contain any untrue statement of a material fact or will omit to state any material fact required to be stated therein or necessary in order to make the statements therein not misleading. When any related preliminary prospectus was first filed with the Commission (whether filed as part of the Registration Statement or any amendment thereto or pursuant to Rule 424(a) of the Rules) and when any amendment thereof or supplement thereto was first filed with the Commission, such preliminary prospectus as amended or supplemented complied in all material respects with the applicable provisions of the Securities Act and the Rules and did not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein not misleading. If applicable, each Preliminary Prospectus

and the Prospectus delivered to the Underwriters for use in connection with the offering contemplated hereby was identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T. If Rule 434 is used, the Company will comply with the requirements of Rule 434 and the Prospectus shall not be “materially different,” as such term is used in Rule 434, from the Prospectus included in the Registration Statement at the time it became effective. Notwithstanding the foregoing, none of the representations and warranties in this paragraph 2(a) shall apply to statements in, or omissions from, the Registration Statement or the Prospectus made in reliance upon, and in conformity with, information herein or otherwise furnished in writing by the Representatives on behalf of the several Underwriters expressly for use in the Registration Statement or the Prospectus. With respect to the preceding sentence, the Company acknowledges that the only information furnished in writing by the Representatives on behalf of the several Underwriters for use in the Registration Statement or the Prospectus is the information contained under the caption “Underwriting” in the Prospectus.

(b) The Registration Statement is effective under the Securities Act and no stop order preventing or suspending the effectiveness of the Registration Statement or suspending or preventing the use of the Prospectus has been issued by the Commission and no proceedings for that purpose have been instituted or are threatened under the Securities Act. Any required filing of the Prospectus and any supplement thereto pursuant to Rule 424(b) of the Rules has been or will be made in the manner and within the time period required by such Rule 424(b).

(c) The financial statements of the Company (including all notes and schedules thereto) included in the Registration Statement and Prospectus present fairly the financial position of the Company at the dates indicated and the statement of operations, stockholders’ deficit and cash flows of the Company for the periods specified; and such financial statements and related schedules and notes thereto, and the unaudited financial information filed with the Commission as part of the Registration Statement, have been prepared in conformity with generally accepted accounting principles in the United States, consistently applied throughout the periods involved. The summary and selected financial data included in the Prospectus present fairly the

information shown therein as at the respective dates and for the respective periods specified and have been presented on a basis consistent with the consolidated financial statements set forth in the Prospectus. The pro forma financial statements and the related notes thereto included in the Registration Statement and the Prospectus present fairly the information shown therein, have been prepared in accordance with the Commission’s rules and guidelines with respect to pro forma financial statements and have been properly compiled on the bases described therein, and the assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions and circumstances referred to therein.

(d) PricewaterhouseCoopers LLP, whose reports are filed with the Commission as a part of the Registration Statement, is and, during the periods covered by their reports, was an independent public accounting firm as required by the Securities Act and the Rules and is registered with the Public Company Accounting Oversight Board. The Company has no reason to believe that such accountants, in their performance of work for the Company, are in violation of the auditor independence requirement of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith (the “Sarbanes-Oxley Act”).

(e) The statistical and market related data included in the Registration Statement are based on or derived from sources that the Company believes to be reliable and accurate, and the Company has received any consents required from such sources in connection with the inclusion of such data in the Registration Statement.

(f) The Company (i) has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of Delaware, having full corporate power and authority to own or lease its properties and to conduct its business as described in the Registration Statement and the Prospectus; and (ii) is duly qualified to do business as a foreign corporation and is in good standing in all jurisdictions in which the character of the property owned or leased or the nature of the business transacted by it makes qualification necessary except for such jurisdictions where the failure to so qualify individually or in the aggregate would not have a material adverse effect on the assets, properties, financial condition, or in the results of operations, business affairs or business prospects of the Company (a

“Material Adverse Effect”). The Company has no subsidiaries and does not own any capital stock or other equity securities in any other entity, except for instruments or interests held by the Company solely for investment. To the Company’s knowledge, no proceeding has been instituted in any such jurisdiction revoking, limiting or curtailing, or seeking to revoke, limit or curtail, such power and authority or qualification.

(g) The Company has all requisite corporate power and authority, and all necessary authorizations, approvals, consents, orders, licenses, certificates and permits of and from all governmental or regulatory bodies or any other person or entity (collectively, “Permits”), to own, lease and license its assets and properties and conduct its business, all of which are valid and in full force and effect, except where the lack of such Permits, individually or in the aggregate, would not have a Material Adverse Effect. The Company has fulfilled and performed in all material respects all of its material obligations with respect to such Permits and no event has occurred that allows, or after notice or lapse of time would allow, revocation or termination thereof except as would not individually or in the aggregate result in a Material Adverse Effect. Except as may be required under the Securities Act and state and foreign blue sky laws, no other Permits are required to enter into, deliver and perform this Agreement and to issue and sell the Shares.

(h) (i) The Company owns, possesses or has adequate rights to the patents and patent applications, trademarks, trademark applications, trade names, service marks, copyrights, copyright applications, licenses, trade secrets, technology and know-how (the “Company Intellectual Property”) necessary for the conduct of the Company’s business, including the Company Intellectual Property reasonably necessary to develop, manufacture, market and sell the INRatio System in the manner described in the Registration Statement and the Prospectus, except to the extent that the failure to own or possess or have adequate rights to use such Company Intellectual Property would not, individually or in the aggregate, have a Material Adverse Effect.

(ii) Other than as set forth or contemplated in the Registration Statement or the Prospectus, the Company has not received any notice of infringement of, or conflict with, and has no knowledge of any such infringement of, or

conflict with, asserted rights of a third party with respect to the Company Intellectual Property except as would not, individually or in the aggregate, have a Material Adverse Effect.

(iii) Other than as set forth or contemplated in the Registration Statement or the Prospectus or as would not have a Material Adverse Effect, the conduct of the current business of the Company in the manner described in the Prospectus does not infringe, interfere or conflict with any valid claim in an issued patent or other intellectual property right of any third party.

(iv) Other than as set forth or contemplated in the Registration Statement or the Prospectus, no third party, including any academic or governmental organization, possesses rights to the patents, patent applications or patent rights of the Company, which, if exercised would allow such third party to develop products directly competitive with those of the Company except as would not, individually or in the aggregate, have a Material Adverse Effect.

(v) All information material to patentability has been disclosed, or will be disclosed in a timely manner to the U.S. Patent and Trademark Office or similar foreign authority during the prosecution of the Company’s patents and patent applications and no misrepresentation was made to, or material fact withheld from, the U.S. Patent and Trademark Office or similar foreign authority during such prosecution.

(vi) Other than as set forth or contemplated in the Registration Statement or the Prospectus: the Company’s patents are valid and enforceable and are entitled to a statutory presumption of validity and of ownership by the assignee; there are no asserted or, to the Company’s knowledge, unasserted claims of any persons relating to the scope or ownership of any of the Company’s patents; and, to the Company’s knowledge, there are no liens which have been filed against any of the Company’s patents.

(i) The Company does not own any real property. The Company has good and marketable title to all other property owned by it, in each case free and clear of all liens, encumbrances, claims, security interests and defects, except as would not, individually or in the aggregate, have a Material Adverse Effect. All property held under lease by

the Company is held by it under valid, existing and enforceable leases, free and clear of all liens, encumbrances, claims, security interests and defects, except as would not, individually or in the aggregate, have a Material Adverse Effect.

(j) Other than as set forth in the Registration Statement or the Prospectus, (i) there has not been any Material Adverse Effect; and (ii) the Company has not sustained any loss or interference with its assets, businesses or properties (whether owned or leased) from fire, explosion, earthquake, flood or other calamity, whether or not covered by insurance, or from any labor dispute or any court or legislative or other governmental action, order or decree which would have a Material Adverse Effect. Other than as set forth in the Registration Statement or the Prospectus, since the date of the latest balance sheet included in the Registration Statement and the Prospectus, the Company has not (A) issued any securities or incurred any liability or obligation, direct or contingent, for borrowed money, except such liabilities or obligations incurred in the ordinary course of business, (B) entered into any transaction not in the ordinary course of business or (C) declared or paid any dividend or made any distribution on any shares of its stock or redeemed, purchased or otherwise acquired or agreed to redeem, purchase or otherwise acquire any shares of its capital stock.

(k) There is no document, contract or other agreement required to be described in the Registration Statement or Prospectus or to be filed as an exhibit to the Registration Statement which is not described or filed as required by the Securities Act or the Rules. Each description of a document, contract or other agreement in the Registration Statement and the Prospectus accurately reflects in all material respects the terms of the underlying document, contract or other agreement required to be disclosed. Each document, contract or other agreement described in the Registration Statement and Prospectus or filed as an exhibit to the Registration Statement is in full force and effect and is valid and enforceable by and against the Company in accordance with its terms. Neither the Company, nor to the Company’s knowledge, any other party is in default in the observance or performance of any term or obligation to be performed by it under any such document, contract or other agreement, and no event has occurred which with notice or lapse of time or both would constitute such a default, in any

such case which default or event, individually or in the aggregate, would have a Material Adverse Effect. No default exists, and no event has occurred which with notice or lapse of time or both would constitute a default, in the due performance and observance of any term, covenant or condition, by the Company, of any other agreement or instrument to which the Company is a party or by which the Company or its properties or business may be bound or affected which default or event, individually or in the aggregate, would have a Material Adverse Effect.

(l) The Company is not in violation of any term or provision of its charter or bylaws or of any franchise, license, permit, judgment, decree, order, statute, rule or regulation, where the consequences of such violation, individually or in the aggregate, would have a Material Adverse Effect.

(m) Neither the execution, delivery and performance of this Agreement by the Company nor the issuance and sale by the Company of the Shares will give rise to a right to terminate or accelerate the due date of any payment due under, or conflict with or result in the breach of any term or provision of, or constitute a default (or an event which with notice or lapse of time or both would constitute a default) under, or require any consent or waiver under, or result in the execution or imposition of any lien, charge or encumbrance upon any properties or assets of the Company pursuant to the terms of, any indenture, mortgage, deed of trust or other agreement or instrument to which the Company is a party or by which the Company or any of its properties or businesses is bound, or any franchise, license, permit, judgment, decree, order, statute, law, rule or regulation applicable to the Company or violate any provision of the charter or bylaws of the Company, except for such consents or waivers which have already been obtained and are in full force and effect.

(n) The Company has the duly authorized and validly issued outstanding capitalization as of [ ], 2005 as set forth under the caption “Capitalization” in the Prospectus and will have the adjusted capitalization as of [ ], 2005 (giving effect to the closing of the offering contemplated by this Agreement) set forth therein on the each Closing Date, based on the assumptions set forth therein. The certificates evidencing the Shares are in due and proper legal form under Delaware law and have been duly authorized for issuance by

the Company. All of the issued and outstanding shares of Common Stock have been duly authorized and validly issued and are fully paid and nonassessable. All of the issued and outstanding shares of capital stock of the Company were issued in transactions that were exempt from the registration requirements of the Securities Act, without violation of preemptive rights, rights of first refusal or similar rights. There are no statutory preemptive or other similar rights to subscribe for or to purchase or acquire any shares of Common Stock of the Company or any such rights pursuant to the Company’s charter or bylaws or any agreement or instrument to or by which the Company is a party or bound, except as set forth in that certain Amended and Restated Investor Rights Agreement, dated as of February 7, 2005, between the Company and certain of its stockholders. The Shares, when issued and sold pursuant to this Agreement will be duly and validly issued, fully paid and nonassessable and none of them will be issued in violation of any preemptive or other similar right. Except as disclosed in the Registration Statement and the Prospectus, there is no outstanding option, warrant or other right calling for the issuance of, and there is no commitment, plan or arrangement to issue, any share of capital stock of the Company or any security convertible into, or exercisable or exchangeable for, such capital stock. The securities of the Company conform to the descriptions thereof contained in the Registration Statement and the Prospectus.

(o) No holder of any security of the Company has any right, which has not been waived in writing, to have any security owned by such holder included in the Registration Statement or to demand registration of any security owned by such holder for a period of 180 days after the date of this Agreement. Each director and executive officer of the Company and each stockholder of the Company holding over 1% of the Company’s outstanding Common Stock (treating, for purposes of this Section 2(o), each holder of any security convertible into or exercisable or exchangeable for shares of Common Stock or any warrant or other right to acquire shares of Common Stock or any such security as a holder of the shares of Common Stock underlying such security, warrant or right, and treating as outstanding, for purposes of this Section 2(o), each share of Common Stock underlying any such security, warrant or right) has delivered to the Representatives an enforceable written lock-up agreement.

(p) All necessary corporate action has been duly and validly taken by the Company to authorize the execution, delivery and performance of this Agreement and the issuance and sale of the Shares by the Company. This Agreement has been duly and validly authorized, executed and delivered by the Company and constitutes a legal, valid and binding obligation of the Company enforceable against the Company in accordance with its terms, except as the enforceability may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws affecting the enforcement of creditors’ rights generally and by general equitable principles.

(q) The Company is not involved in any labor dispute nor, to the knowledge of the Company, is any such dispute threatened, which dispute would have a Material Adverse Effect. The Company is not aware of any existing or imminent labor disturbance by the employees of any of its principal suppliers or contractors which would have a Material Adverse Effect. The Company is not aware of any threatened or pending litigation between the Company and any of its executive officers which, if adversely determined, could have a Material Adverse Effect and has no reason to believe that such officers will not remain in the employment of the Company.

(r) No relationship, direct or indirect, exists between or among the Company, on the one hand, and the current or former directors, officers, stockholders, customers or suppliers of the Company, on the other hand, which is required to be described in the Registration Statement and the Prospectus that is not so described.

(s) The Company has not taken, and will not take, directly or indirectly, any action designed to or which might reasonably be expected to cause or result in, or which has constituted or which might reasonably be expected to constitute, the stabilization or manipulation of the price of the Common Stock or any security of the Company to facilitate the sale or resale of any of the Shares.

(t) The Company has filed all Federal, state, local and foreign tax returns which are required to be filed through the date hereof, which returns are true and correct in all material respects or has received timely extensions thereof, and has paid all taxes shown on such returns and all assessments received by it to the extent that the same are

material and have become due. There are no tax audits or investigations pending, which if adversely determined would have a Material Adverse Effect; nor, to the Company’s knowledge, are there any material proposed additional tax assessments against the Company.

(u) The Shares have been duly authorized for quotation on the National Association of Securities Dealers Automated Quotation (“Nasdaq”) National Market System and listed and duly admitted to trading on the Nasdaq National Market. A registration statement has been filed on Form 8-A pursuant to Section 12 of the Exchange Act with respect to the Common Stock, which registration statement complies in all material respects with the requirements of the Exchange Act.

(v) The books, records and accounts of the Company accurately and fairly reflect, in reasonable detail, the transactions in, and dispositions of, the assets of, and the results of operations of, the Company. The Company maintains a system of internal accounting controls sufficient to provide reasonable assurances that (i) transactions are executed in accordance with management’s general or specific authorizations, (ii) transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles and to maintain asset accountability, (iii) access to assets is permitted only in accordance with management’s general or specific authorization and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(w) The Company is insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as are prudent and customary in the businesses in which they are engaged, all of which insurance is in full force and effect. The Company is in compliance with the terms of such policies and instruments in all material respects; and the Company does not have any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at then prevailing rates applicable to similarly situated companies. The Company has not been denied any insurance coverage which it has sought or for which it has applied.

(x) Each approval, clearance, consent, order, authorization, designation, declaration or filing of, by or with any regulatory, administrative or other governmental body necessary or required to be obtained or performed by the Company in connection with the execution and delivery by the Company of this Agreement and the consummation of the transactions herein contemplated (except such additional steps as may be required by the National Association of Securities Dealers, Inc. (the “NASD”) or may be necessary to qualify the Shares for public offering by the Underwriters under the state securities or blue sky laws) has been obtained or made and is in full force and effect.

(y) The Company has not failed to file with the applicable regulatory authorities (including, without limitation, the United States Food and Drug Administration (“FDA”) or any foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA) any material filing, premarket application or notification, declaration, listing, registration, report or submission that is required to be filed, in order for the Company to conduct its business as described in the Registration Statement and the Prospectus. All such filings, premarket applications or notifications, declarations, listings, registrations, reports or submissions were in compliance in all material respects with applicable laws and regulations when filed and no material deficiencies have been asserted against the Company by any applicable regulatory authority (including, without limitation, the FDA or any foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA) with respect to any such filings, premarket applications or notifications, declarations, listings, registrations, reports or submissions. Except to the extent disclosed in the Registration Statement and the Prospectus, the Company has operated and currently is in compliance in all material respects with applicable provisions of the Federal Food, Drug, and Cosmetic Act (“FFDCA”), all applicable FDA regulations, and the In Vitro Diagnostic Medical Devices Directive 98/79/EC. Except to the extent disclosed in the Registration Statement and the Prospectus, the Company has not received any notices or other correspondence from the FDA, any Competent Authority in the European Union, or any other foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA, stating that the Company is not in

compliance with applicable laws or regulations administered by those governmental or regulatory authorities.

(z) Except as disclosed in the Registration Statement and the Prospectus, there is no action, suit, claim, proceeding or investigation pending or, to the Company’s knowledge, threatened against the Company before or by any court, regulatory body or administrative agency or any other governmental agency or body, domestic or foreign, that (i) questions the validity of the capital stock of the Company or this Agreement or any action taken or to be taken by the Company pursuant to or in connection with this Agreement, (ii) is required to be disclosed in the Registration Statement and the Prospectus and is not so disclosed (and such proceedings, if any, as are summarized in the Registration Statement and the Prospectus are accurately summarized in all material respects); or (iii) may have a Material Adverse Effect.

(aa) The Company is in compliance in all material respects with all rules, laws and regulations relating to the use, treatment, storage and disposal of toxic substances and protection of health or the environment (“Environmental Laws”) which are applicable to its business; (ii) the Company has not received any notice from any governmental authority or third party of an asserted claim under Environmental Laws; (iii) the Company has received all permits, licenses or other approvals required of it under applicable Environmental Laws to conduct its business and is in compliance with all terms and conditions of any such permit, license or approval except for such failures to so receive or comply as would not have a Material Adverse Effect; (iv) to the Company’s knowledge, no facts currently exist that will require the Company to make future material capital expenditures to comply with Environmental Laws; and (v) to the Company’s knowledge, no property which is or has been owned, leased or occupied by the Company has been designated as a Superfund site pursuant to the Comprehensive Environmental Response, Compensation and Liability Act of 1980, as amended (42 U.S.C. Section 9601, et. seq.) (“CERCLA “) or otherwise designated as a contaminated site under applicable state or local law. The Company has not been named as a “potentially responsible party” under CERCLA.

(bb) The Company is not and, after giving effect to the offering and sale of the Shares and the application of proceeds thereof as described in the Prospectus, will not be

an “investment company” within the meaning of the Investment Company Act of 1940, as amended (the “Investment Company Act”).

(cc) The Company does not, directly or indirectly, including through any subsidiary, have any outstanding personal loans or other credit extended to or for any director or executive officer.

(dd) Other than as set forth or contemplated in the Registration Statement or the Prospectus or as would not have a Material Adverse Effect, neither the Company nor, to the Company’s knowledge, any director, officer, agent or employee of the Company, has not, directly or indirectly, while acting on behalf of the Company (i) used any corporate funds for unlawful contributions, gifts, entertainment or other unlawful expenses relating to political activity; (ii) made any unlawful payment to foreign or domestic government officials or employees or to foreign or domestic political parties or campaigns from corporate funds; (iii) violated any provision of the Foreign Corrupt Practices Act of 1977, as amended; or (iv) made any other unlawful payment.

(ee) Except as described in the Prospectus, the Company has not sold or issued any securities during the six-month period preceding the date of the Prospectus, including any sales pursuant to Rule 144A under, or Regulations D or S of, the Securities Act.

(ff) The Company has fulfilled its obligations, if any, under the minimum funding standards of Section 302 of the U.S. Employee Retirement Income Security Act of 1974 (“ERISA”) and the regulations and published interpretations thereunder with respect to each “plan” as defined in Section 3(3) of ERISA and such regulations and published interpretations in which its employees are eligible to participate and each such plan is in compliance in all material respects with the presently applicable provisions of ERISA and such regulations and published interpretations. No “Reportable Event” (within the meaning of Section 4043 of ERISA) has occurred with respect to any “Employee Benefit Pension Plan” (as defined in Section 3(2) of ERISA) for which the Company could have any liability.

(gg) The Company has not incurred any liability for a fee, commission, or other compensation on account of the employment of a broker or finder in connection with the

(hh) Each of the Company, its directors and officers has not distributed and will not distribute prior to the later of (i) the Firm Shares Closing Date, or any Option Shares Closing Date, and (ii) completion of the distribution of the Shares, any offering material in connection with the offering and sale of the Shares other than any Preliminary Prospectus, the Prospectus, the Registration Statement and other materials, if any, permitted by the Securities Act.

(ii) Except as disclosed in the Registration Statement and the Prospectus, the Company is not aware of (i) any significant deficiency or material weakness in the design or operation of the Company’s internal control over financial reporting which is reasonably likely to adversely affect the Company’s ability to record, process, summarize and report financial information or (ii) any fraud, whether or not material, that involves management or other employees who have a significant role in the Company’s internal control over financial reporting; and no change in the Company’s internal control over financial reporting occurred during or since the Company’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

3. Conditions of the Underwriters’ Obligations. The obligations of the Underwriters under this Agreement are several and not joint. The respective obligations of the Underwriters to purchase the Shares are subject to each of the following terms and conditions:

(a) Notification that the Registration Statement has become effective shall have been received by the Representatives and the Prospectus shall have been timely filed with the Commission in accordance with Section 4(a) of this Agreement.

(b) No order preventing or suspending the use of any preliminary prospectus or the Prospectus shall have been or shall be in effect and no order suspending the effectiveness of the Registration Statement shall be in effect and no proceedings for such purpose shall be pending before or threatened by the Commission, and any requests for additional information on the part of the Commission (to be included in the Registration Statement or the Prospectus or otherwise) shall have been complied with to the satisfaction

of the Commission and the Representatives. If the Company has elected to rely upon Rule 430A, Rule 430A information previously omitted from the effective Registration Statement pursuant to Rule 430A shall have been transmitted to the Commission for filing pursuant to Rule 424(b) within the prescribed time period and the Company shall have provided evidence satisfactory to the Underwriters of such timely filing, or a post-effective amendment providing such information shall have been promptly filed and declared effective in accordance with the requirements of Rule 430A. If the Company has elected to rely upon Rule 434, a term sheet shall have been transmitted to the Commission for filing pursuant to Rule 424(b) within the prescribed time period.

(c) The Representatives shall be satisfied that (i) the representations and warranties of the Company contained in this Agreement and in the certificates delivered pursuant to Section 3(d) shall be true and correct when made and on and as of each Closing Date as if made on such date; (ii) since the Effective Date, no event as occurred that should have been set forth in a supplement or amendment to the Prospectus that has not been set forth in an effective supplement or amendment and (iii) since the respective dates as of which information is given in the Registration Statement in the form in which it originally became effective and the Prospectus contained therein, there has not been any material adverse change or any development involving a prospective material adverse change in the business, properties, financial condition or results of operations of the Company, and since such dates, the Company has not entered into any material transaction not referred to in the Registration Statement in the form in which it originally became effective and the Prospectus contained therein. The Company shall have performed all covenants and agreements and satisfied all the conditions contained in this Agreement required to be performed or satisfied by them at or before such Closing Date.

(d) The Representatives shall have received on each Closing Date a certificate, addressed to the Representatives and dated such Closing Date, of the chief executive or chief operating officer and the chief financial officer or chief accounting officer of the Company to the effect that: (i) the representations, warranties and agreements of the Company in this Agreement were true and correct when made and are true and correct as of such Closing Date;

(ii) the Company has performed all covenants and agreements and satisfied all conditions on its part to be performed or satisfied hereunder on or prior to such Closing Date; (iii) such officers have carefully examined the Registration Statement and the Prospectus and, in such officers’ opinion (A) as of the Effective Date, the Registration Statement and Prospectus did not include any untrue statement of a material fact and did not omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading, and (B) since the Effective Date no event has occurred which should have been set forth in a supplement or otherwise required an amendment to the Registration Statement or the Prospectus; and (iv) no stop order suspending the effectiveness of the Registration Statement has been issued and, to such officers’ knowledge, no proceedings for that purpose have been instituted or are pending under the Securities Act.

(e) The Representatives shall have received a certificate on each Closing Date signed by the Secretary of the Company to the effect that, as of such Closing Date, the Secretary certifies as to (i) (A) the accuracy and completeness of the Company’s certificate of incorporation and bylaws, (B) the resolutions of the Board of Directors and any committee thereof relating to the offering contemplated hereby, (C) the form of stock certificate representing the Shares and (D) copies of all communications with the Commission; (ii) the execution and delivery of this Agreement; (iii) the incumbency and signature of persons signing this Agreement, the Registration Statement and other related documents; (iv) the approval of the Shares for listing on the Nasdaq National Market; and (v) such other matters as Underwriters’ counsel may reasonably request.

(f) The Representatives shall have been furnished evidence in the usual written or electronic form from the appropriate authorities of the applicable jurisdictions, or other evidence satisfactory to the Representatives, of the good standing and qualifications of the Company.

(g) The Representatives shall have received, at the time this Agreement is executed and on each Closing Date a signed letter from PricewaterhouseCoopers LLP addressed to the Representatives and dated, respectively, the date of this Agreement and each such Closing Date, in form and substance reasonably satisfactory to the Representatives

containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement and the Prospectus.

(h) The Representatives shall have received on each Closing Date from Wilson, Sonsini, Goodrich & Rosati, P.C., counsel for the Company, an opinion, addressed to the Representatives and dated such Closing Date, and stating in effect that:

(i) The Company is a corporation duly incorporated and validly existing under, and by virtue of the laws of the State of Delaware, and is in good standing under such laws. The Company is qualified to do business as a foreign corporation in the State of California.

(ii) The Company has all requisite corporate power and authority to own or lease, as the case may be, and to operate its properties and to conduct its business as now being conducted and as described in the Registration Statement and the Prospectus and to enter into and perform its obligations under this Agreement and to issue and sell the Shares.

(iii) The authorized, issued and outstanding capital stock of the Company is as set forth in the Registration Statement and the Prospectus under the caption “Capitalization” as of the dates stated therein and, since such dates, there has been no change in the capital stock of the Company except for subsequent issuances, if any, pursuant to this Agreement or pursuant to reservations, agreements or employee benefit plans referred to in the Prospectus or pursuant to the exercise of convertible securities or options referred to in the Prospectus.

(iv) All of the outstanding shares of capital stock of the Company have been duly and validly authorized and issued and are fully paid and nonassessable. The Shares to be issued and sold by the Company pursuant to this Agreement have been duly authorized for issuance and sale to the Underwriters pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration therefor set forth herein, will be validly issued, fully paid and nonassessable. The stockholders of the Company have no preemptive rights contained in the Company’s certificate of incorporation or bylaws, and, to the knowledge of counsel, the stockholders of the Company have no contractual, written preemptive rights, rights of first refusal or other similar rights of the Company with respect to the Shares that have not otherwise been waived in writing. Except as disclosed in the Registration Statement and the Prospectus, there is no outstanding option (other than those issued in the ordinary course of business under the Company’s employee benefit plans), warrant or other right calling for the issuance of, and no commitment, plan or arrangement to

issue, any share of stock of the Company or any security convertible into, exercisable for, or exchangeable for stock of the Company. The Common Stock, and the Shares conform in all material respects to the descriptions thereof contained in the Registration Statement and the Prospectus. The form of certificate used to evidence the Common Stock complies in all material respects with all applicable statutory requirements, with any applicable requirements of the certificate of incorporation or bylaws of the Company and the requirements of the Nasdaq National Market. Except as described in the Registration Statement and the Prospectus and as have been waived in writing, to the knowledge of counsel there are no persons with registration rights or other similar rights to have any securities registered pursuant to the Registration Statement or otherwise registered by the Company under the Securities Act.

(v) All necessary corporate action has been duly and validly taken by the Company to authorize the execution, delivery and performance of this Agreement and the issuance and sale of the Shares. This Agreement has been duly and validly authorized, executed and delivered by the Company.

(vi) The execution, delivery and performance of this Agreement by the Company (including the issuance and sale by the Company of the Shares) will not violate any provisions of the Company’s certificate of incorporation or bylaws, or any provision of applicable federal or state law, rule or regulation known to counsel to be customarily applicable to transactions of this nature nor will it violate, or constitute a breach or default under, any contract or agreement filed as an exhibit to the Registration Statement pursuant to Item 601(b)(10) of Regulation S-K to which the Company is a party.

(vii) No consent, approval, authorization, license, registration, qualification or order of or filing with any court or governmental agency or regulatory body is required for the due authorization, execution, delivery or performance of this Agreement by the Company or the consummation of the transactions contemplated hereby, except such as have been obtained under the Securities Act and such as may be required under state securities or blue sky laws in connection with the purchase and distribution of the Shares by the several Underwriters or under the bylaws, rules or regulations of the NASD.

(viii) To such counsel’s knowledge, there is no action, suit, proceeding or other investigation, before any court or before or by any public authority, body or board pending or threatened against, or involving the assets, properties or businesses of, the Company which is required to be disclosed in the Registration Statement and the Prospectus and is not so disclosed.

(ix) The information in the Prospectus under the captions “Description of Capital Stock,” “Business-Government Regulation,” “Shares Eligible for Future Sale”, “Related Party Transactions,” and in the Registration Statement under Items 14 and 15 of Part II, in each case insofar as such statements constitute summaries of legal matters, documents or proceedings referred to therein, fairly

present, in all material respects, the information called for with respect to such legal matters, documents and proceedings and fairly summarize the matters referred to therein in all material respects. Accurate copies of all documents, contracts and other agreements required to be filed as exhibits to, or described in, the Registration Statement have been so filed with the Commission or are fairly described in the Registration Statement, as the case may be.

(x) The Registration Statement, all Preliminary Prospectuses and the Prospectus and each amendment or supplement thereto (except for the financial statements and schedules and other financial data included therein, as to which such counsel need express no opinion) comply as to form in all material respects with the requirements of the Securities Act and the Rules.

(xi) The Registration Statement is effective under the Securities Act, and to the knowledge of counsel, no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for that purpose have been instituted or are threatened, pending or contemplated. Any filing of the Prospectus and any supplement thereto required on or prior to the Closing Date pursuant to Rule 424(b) under the Securities Act has been made in the manner and within the time period required by such Rule 424(b).

(xiii) The Company is not required to register as an “investment company” as such term is defined in the Investment Company Act.

To the extent deemed advisable by such counsel, such counsel may rely as to matters of fact on certificates of responsible officers of the Company and public officials and on the opinions of other counsel reasonably satisfactory to the Representatives as to matters which are governed by laws other than the laws of the State of California, the General Corporation Law of the State of Delaware and the Federal laws of the United States; provided that such counsel shall state that in their opinion that the Underwriters and they are justified in relying on such other opinions. Copies of such certificates and other opinions shall be furnished to the Representatives and counsel for the Underwriters.

In addition, such counsel shall state that such counsel has participated in conferences with certain officers, its intellectual property counsel and other representatives of the Company, representatives of the Representatives, counsel for the Representatives and representatives of the independent public accounting firm of the Company, at which conferences the contents of the Registration Statement and the Prospectus and related matters were reviewed and discussed and, although such counsel does not assume any responsibility for the accuracy, completeness or fairness of the statements contained in the Registration Statement or Prospectus (except as specified in the foregoing opinion), no facts have come to the attention of such counsel, through such review and discussion as described herein, which have caused such counsel to believe that (i) as of its effective date, the Registration Statement or any amendment thereto

(other than the financial statements and related schedules and the financial and statistical data derived from such financial statements or schedules, as to which we express no belief) contained any untrue statement of a material fact or omitted to state any material fact required to be stated therein or necessary in order to make the statements therein not misleading, or (ii) as of its issue date or as of the Closing Date, the Prospectus or any amendment or supplement thereto (other than the financial statements and related schedules and the financial and statistical data derived from such financial statements or schedules, as to which we express no belief) contained or contains any untrue statement of a material fact or omitted to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(i) The Representatives shall have received on each Closing Date an opinion from Jerrold J. Litzinger, special intellectual property counsel to the Company, addressed to the Representatives and dated such Closing Date, and stating in effect that:

(i) To the best of such counsel’s knowledge, the Company owns, possesses or has adequate rights to use the patents and patent applications, inventions, technology and know-how (the “Company Intellectual Property”) reasonably necessary to develop, manufacture, market and sell the INRatio System in the manner described in the Registration Statement and the Prospectus, except to the extent that the failure to own or possess or have adequate rights to use such Company Intellectual Property would not, individually or in the aggregate, have a Material Adverse Effect.

(ii) To the best of such counsel’s knowledge, other than as set forth or contemplated in the Registration Statement and the Prospectus, the Company has not received any notice of infringement of, or conflict with, and such counsel has no knowledge of any such infringement of, or conflict with, asserted rights of a third party with respect to the Company Intellectual Property except as would not, individually or in the aggregate, have a Material Adverse Effect.

(iii) To the best of such counsel’s knowledge, other than as set forth or contemplated in the Registration Statement and the Prospectus or as would not have a Material Adverse Effect, the conduct of the current and future business of the Company in the manner described in the Prospectus does not and will not infringe, interfere or conflict with any valid claim in an issued patent or other intellectual property right of any third party.

(iv) To the best of such counsel’s knowledge, other than as set forth or contemplated in the Registration Statement and the Prospectus, no third party, including any academic or governmental organization, possesses or could obtain rights to the patents, patent applications or patent rights of the Company, which, if exercised would allow such third party to develop products competitive with

those of the Company would, individually or in the aggregate, have a Material Adverse Effect.

(v) To the best of such counsel’s knowledge, all information material to patentability has been disclosed, or will be disclosed in a timely manner to the U.S. Patent and Trademark Office or similar foreign authority during the prosecution of the Company’s patents and patent applications and no misrepresentation was made to, or material fact withheld from, the U.S. Patent and Trademark Office or similar foreign authority during such prosecution.

(vi) To the best of such counsel’s knowledge, the statements relating to legal matters, documents or proceedings included in the Prospectus under the captions “Risk Factors – Our inability to adequately protect our intellectual property could allow our competitors and others to produce products based on our technology, which could substantially impair our ability to compete”; “Risk Factors – We may become subject to claims of infringement or misappropriation of the intellectual property rights of others, which could prohibit us from shipping affected products, require us to obtain licenses from third parties or to develop non-infringing alternatives, and subject us to substantial monetary damages and injunctive relief”; “Risk Factors – The prosecution and enforcement of patents licensed to us by third parties are not within our control, and without these technologies, our product may not be successful and our business would be harmed”; and “Business-Intellectual Property” fairly summarize in all material respects such matters, documents or proceedings.

(vii) To the best of such counsel’s knowledge, the Company’s patents are valid and enforceable and are entitled to a statutory presumption of validity and of ownership by the assignee; there are no asserted or unasserted claims of any persons relating to the scope or ownership of any of the Company’s patents; and there are no liens which have been filed against any of the Company’s patents.

(j) The legality and sufficiency of the sale of the Shares hereunder and the validity and form of the certificates representing the Shares, all corporate proceedings and other legal matters incident to the foregoing, and the form of the Registration Statement and of the Prospectus (except as to the financial statements and financial information contained therein) shall have been approved at or prior to the Closing Date by Morgan, Lewis & Bockius LLP, counsel for the Underwriters. The Representatives shall have received on each Closing Date from Morgan, Lewis & Bockius LLP an opinion, addressed to the Representatives and dated such Closing Date, with respect to the issuance and sale of the Shares, the Registration Statement and the Prospectus and such other related matters as the Underwriters reasonably may request and such counsel shall have received such

documents and other information from the Company as they request to enable them to pass upon such matters.

(k) The Representatives shall have received copies of the lock up agreements executed by the directors, executive officers and each stockholder of the Company holding over 1% of the Company’s outstanding Common Stock (treating, for purposes of this Section 3(l), each holder of any security convertible into or exercisable or exchangeable for shares of Common Stock or any warrant or other right to acquire shares of Common Stock or any such security as a holder of the shares of Common Stock underlying such security, warrant or right, and treating as outstanding, for purposes of this Section 3(l), each share of Common Stock underlying any such security, warrant or right).

(l) The Shares shall have been approved for quotation on the Nasdaq National Market.

(m) All outstanding shares of the Company’s Series A-3 Convertible Preferred Stock, $0.001 par value per share, Series B-3 Convertible Preferred Stock, $0.001 par value per share and Series C-3 Convertible Preferred Stock, $0.001 par value per share (collectively, the “Preferred Stock”), shall have converted into the number of shares of Common Stock, and shall have converted in the manner, set forth in the Registration Statement and the Prospectus; the Amended and Restated Certificate of Incorporation of the Company and the Amended and Restated Bylaws of the Company, each in the form filed as an exhibit to the Registration Statement, shall have been duly authorized and approved in accordance with the Delaware General Corporation Law and shall have become, or, concurrently with the closing of the sale of the Firm Shares to the Underwriters pursuant to this Agreement, shall become, effective and in full force and effect.

(n) The Company shall have furnished or caused to be furnished to the Representatives such further certificates or documents as the Representatives shall have reasonably requested.

(a) The Company covenants and agrees with each of the several Underwriters as follows:

(i) The Company will (A) prepare and timely file with the Commission under Rule 424(b) a Prospectus containing information previously omitted at the time of effectiveness of the Registration Statement in reliance on Rule 430A; and (B) not file with the Commission any amendment to the Registration Statement or supplement to the Prospectus of which the Underwriters shall not previously have been advised and furnished with a copy a reasonable period of time prior to the proposed filing and as to which the Underwriters shall not have given their consent or which is not in compliance with the Securities Act or the Rules.

(ii) The Company shall promptly advise the Representatives in writing (A) when any post-effective amendment to the Registration Statement shall have become effective or any supplement to the Prospectus shall have been filed, (B) of any request by the Commission for any amendment of the Registration Statement or the Prospectus or for any additional information, (C) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or of any order preventing or suspending the use of any preliminary prospectus or the institution or threatening of any proceeding for that purpose and (D) of the receipt by the Company of any notification with respect to the suspension of the qualification of the Shares for sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose. The Company shall use its best efforts to prevent the issuance of any such stop order and, if issued, to obtain as soon as possible the withdrawal thereof.

(iii) If, at any time when a prospectus relating to the Shares is required to be delivered under the Securities Act and the Rules in connection with sales by any Underwriter or dealer, any event occurs as a result of which the Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, or if it shall be necessary to amend or supplement the Prospectus to comply with the Securities Act or the Rules, the Company promptly shall prepare and file with the Commission, subject to paragraph (i) of this Section 4(a), an amendment or supplement which shall correct such statement or omission or an amendment which shall effect such compliance.

(iv) The Company shall make generally available to its security holders and to the Representatives as soon as practicable, but not later than 45 days after the end of the 12-month period beginning at the end of the fiscal quarter of the Company during which the Effective Date occurs (or 90 days if such 12-month period coincides with the Company’s fiscal year), an earning statement (which need not be audited) of the Company, covering such 12-month period, which shall satisfy the provisions of Section 11(a) of the Securities Act (and, at the option of the Company, Rule 158 of the Rules).

(v) The Company shall furnish to the Representatives and counsel for the Underwriters, without charge, signed copies of the Registration Statement

(including all exhibits thereto and amendments thereof) and to each other Underwriter a copy of the Registration Statement (without exhibits thereto) and all amendments thereof and, so long as delivery of a prospectus by an Underwriter or dealer may be required by the Securities Act or the Rules, as many copies of any preliminary prospectus and the Prospectus and any amendments thereof and supplements thereto as the Representatives may reasonably request. If applicable, the copies of the Registration Statement and Prospectus and each amendment and supplement thereto furnished to the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

(vi) The Company shall cooperate with the Representatives and their counsel in endeavoring to qualify the Shares for offer and sale in connection with the offering under the laws of such jurisdictions as the Representatives may designate and shall maintain such qualifications in effect so long as required for the distribution of the Shares; provided, however, that the Company shall not be required in connection therewith, as a condition thereof, to qualify as a foreign corporation or to execute a general consent to service of process in any jurisdiction or subject itself to taxation as doing business in any jurisdiction.

(vii) The Company, during the period when the Prospectus is required to be delivered under the Securities Act and the Rules or the Exchange Act, will file all reports and other documents required to be filed with the Commission pursuant to Section 13, 14 or 15 of the Exchange Act within the time periods required by the Exchange Act and the regulations promulgated thereunder.

(viii) The Company will be in compliance, upon the Firm Shares Closing Date, with all applicable provisions of the Sarbanes-Oxley Act.

(ix) Without the prior written consent of Lazard Capital Markets LLC and W.R. Hambrecht + Co., LLC, for a period of 180 days after the date of this Agreement, the Company and each of its individual directors and executive officers shall not issue, sell or register with the Commission (other than on Form S-8 or on any successor form), or otherwise dispose of, directly or indirectly, any equity securities of the Company (or any securities convertible into, exercisable for or exchangeable for equity securities of the Company), except for the issuance of the Shares pursuant to the Registration Statement and the issuance of shares pursuant to the Company’s existing stock incentive plans and outstanding warrants as described in the Registration Statement and the Prospectus. In the event that during this period, (A) any shares are issued pursuant to the Company’s existing stock incentive plans that are exercisable during such 180-day period or (B) any registration is effected on Form S-8 or on any successor form relating to shares that are exercisable during such 180-day period, the Company shall obtain the written agreement of such grantee or purchaser or holder of such registered securities that, for a period of 180 days after the date of this Agreement, such person will not, without the prior written consent of Lazard Capital Markets LLC and W.R. Hambrecht + Co., LLC, offer for sale, sell, distribute, grant any option for the sale of, or otherwise dispose of,

directly or indirectly, or exercise any registration rights with respect to, any shares of Common Stock (or any securities convertible into, exercisable for, or exchangeable for any shares of Common Stock) owned by such person. If (1) during the period that begins on the date that is 17 calendar days before the last day of the 180-day lock-up period and ends on the last day of the 180-day lock-up period, (a) the Company issues an earnings release, (b) the Company publicly announces material news or (c) a material event relating to the Company occurs; or (2) prior to the expiration of the 180-day lock-up period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 180-day lock-up period, then the restrictions in this Agreement, unless otherwise waived by the Representatives in writing, shall continue to apply until the expiration of the date that is 18 calendar days after the date on which (a) the Company issues the earnings release, (b) the Company publicly announces material news or (c) a material event relating to the Company occurs.

(x) On or before completion of the offering contemplated hereby, the Company shall make all filings required under applicable securities laws and by the Nasdaq National Market (including any required registration under the Exchange Act).

(xi) Prior to the later of the Firm Shares Closing Date and any Option Shares Closing Date, the Company will issue no press release or other communications directly or indirectly and hold no press conference with respect to the Company, the condition, financial or otherwise, or the earnings, business affairs or business prospects of any of them, or the offering of the Shares without the prior written consent of the Representatives unless in the judgment of the Company and its counsel, and after notification to the Representatives, such press release or communication is required by law.

(xii) The Company will apply the net proceeds from the offering of the Shares in the manner set forth under “Use of Proceeds” in the Prospectus.

(xiii) The Company will maintain a transfer agent and, if necessary under the jurisdiction of incorporation of the Company, a registrar (which may be the same entity as the transfer agent) for its Common Stock.

(xiv) The Company will not take, directly or indirectly, and will use its best efforts to cause its officers, directors or affiliates not to take, directly or indirectly, any action designed to, or that might in the future be expected to cause or result in, stabilization or manipulation of the price of any securities of the Company.

(b) The Company agrees to pay, or reimburse if paid by the Representatives, whether or not the transactions contemplated hereby are consummated or this Agreement is terminated, all costs and expenses incident to the public

offering of the Shares and the performance of the obligations of the Company under this Agreement including, without limitation, those relating to: (i) the preparation, printing, filing and distribution of the Registration Statement including all exhibits thereto, each preliminary prospectus, the Prospectus, all amendments and supplements to the Registration Statement and the Prospectus, and the printing, filing and distribution of this Agreement; (ii) the preparation and delivery of certificates for the Shares to the Underwriters; (iii) the registration or qualification of the Shares for offer and sale under the securities or blue sky laws of the various jurisdictions referred to in Section 4(a)(vi), including the reasonable fees and disbursements of counsel for the Underwriters in connection with such registration and qualification and the preparation, printing, distribution and shipment of preliminary and supplementary blue sky memoranda; (iv) the furnishing (including costs of shipping and mailing) to the Representatives and to the Underwriters of copies of each preliminary prospectus, the Prospectus and all amendments or supplements to the Prospectus, and of the several documents required by this Section 4 to be so furnished, as may be reasonably requested for use in connection with the offering and sale of the Shares by the Underwriters or by dealers to whom Shares may be sold; (v) the filing fees of the NASD in connection with its review of the terms of the public offering and reasonable fees and disbursements of counsel for the Underwriters in connection with such review (up to a maximum of $40,000); (vi) inclusion of the Shares for quotation on the Nasdaq National Market; (vii) all transfer taxes, if any, with respect to the sale and delivery of the Shares by the Company to the Underwriters; (viii) the costs and charges of any transfer agent, registrar or depositary; (ix) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken with the Company’s prior approval in connection with the marketing of the offering of the Shares, including, without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations, travel and lodging expenses of the officers of the Company and any such consultants, and the cost of any aircraft chartered in connection with the road show; and (x) all expenses in connection with any offer and sale of the Shares outside of the United States, including filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection with offers and sales outside of the United States. Subject to the provisions

of Section 7, the Underwriters agree to pay, whether or not the transactions contemplated hereby are consummated or this Agreement is terminated, all costs and expenses incident to the performance of the obligations of the Underwriters under this Agreement not payable by the Company pursuant to the preceding sentence, including, without limitation, the fees and disbursements of counsel for the Underwriters and the travel and lodging expenses of the Representatives incurred in connection with the road show.

(a) The Company agrees to indemnify and hold harmless each Underwriter and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act against any and all losses, claims, damages and liabilities, joint or several (including any reasonable investigation, legal and other expenses incurred in connection with, and any amount paid in settlement of, any action, suit or proceeding or any claim asserted), to which such Underwriters, or any of such Underwriters, may become subject under the Securities Act, the Exchange Act or other Federal or state law or regulation, at common law or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of a material fact contained in any preliminary prospectus, the Registration Statement or the Prospectus, or any amendment thereof or supplement thereto, or arise out of or are based upon any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading; provided, however, that such indemnity shall not inure to the benefit of any Underwriter (or any person controlling such Underwriter) on account of any losses, claims, damages or liabilities if such untrue statement or omission or alleged untrue statement or omission was made in such preliminary prospectus, the Registration Statement or the Prospectus, or such amendment or supplement thereto in reliance upon and in conformity with written information furnished to the Company by the Representatives on behalf of any Underwriter expressly for use therein. This indemnity agreement will be in addition to any liability which the Company may otherwise have.

(b) Each Underwriter agrees to indemnify and hold harmless the Company and each person, if any, who

controls the Company within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, each director of the Company, and each officer of the Company who signs the Registration Statement, against any and all losses, claims, damages and liabilities (including any reasonable investigation, legal and other expenses incurred in connection with, and any amount paid in settlement of, any action, suit or proceeding or any claim asserted) to which such party may become subject, under the Securities Act, the Exchange Act, or other Federal or state law or regulation, at common law or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of a material fact contained in any preliminary prospectus, the Registration Statement or the Prospectus, or any amendment thereof or supplement thereto, or arise out of or are based upon any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in any preliminary prospectus, the Registration Statement or the Prospectus or any such amendment or supplement thereto in reliance upon and in conformity with written information furnished to the Company by such Underwriter through the Representatives expressly for use therein; provided, however, that the obligation of each Underwriter to indemnify the Company (including any controlling person, director or officer thereof) shall be limited to the net proceeds received by the Company from such Underwriter. This indemnity agreement will be in addition to any liability which the Underwriters may otherwise have.

(c) Any party that proposes to assert the right to be indemnified under this Section 5 will, promptly after receipt of notice of commencement of any action, suit or proceeding against such party in respect of which a claim is to be made against an indemnifying party or parties under this Section 5, notify each such indemnifying party of the commencement of such action, suit or proceeding, enclosing a copy of all papers served. No indemnification provided for in Section 5(a) or 5(b) shall be available to any party who shall fail to give notice as provided in this Section 5(c) if the party to whom notice was not given was unaware of the proceeding to which such notice would have related and was materially prejudiced by the failure to give such notice but

the omission so to notify such indemnifying party of any such action, suit or proceeding shall not relieve it from any liability that it may have to any indemnified party for contribution or otherwise than under this Section 5. In case any such action, suit or proceeding shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate in, and, to the extent that it shall wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel reasonably satisfactory to such indemnified party, and after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof and the approval by the indemnified party of such counsel, the indemnifying party shall not be liable to such indemnified party for any legal or other expenses, except as provided below and except for the reasonable costs of investigation subsequently incurred by such indemnified party in connection with the defense thereof. The indemnified party shall have the right to employ its counsel in any such action, but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the employment of counsel by such indemnified party has been authorized in writing by the indemnifying parties, (ii) the indemnified party shall have been advised by counsel that there may be one or more legal defenses available to it which are different from or in addition to those available to the indemnifying party (in which case the indemnifying parties shall not have the right to direct the defense of such action on behalf of the indemnified party) or (iii) the indemnifying parties shall not have employed counsel to assume the defense of such action within a reasonable time after notice of the commencement thereof, in each of which cases the fees and expenses of counsel shall be at the expense of the indemnifying parties.

(d) An indemnifying party shall not be liable for any settlement of any action, suit, and proceeding or claim effected without its written consent, which consent shall not be unreasonably withheld or delayed.

(e) No indemnifying party shall, without the written consent of the indemnified party, effect any settlement of any pending or threatened proceeding in respect of which any indemnified party is or could have been a party and indemnification could have been sought hereunder by such indemnified party, unless such settlement (x) includes an

unconditional release of such indemnified party from all liability on claims that are the subject matter of such proceeding and (y) does not include any statement as to or any admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

6. Contribution. In order to provide for just and equitable contribution in circumstances in which the indemnification provided for in Section 5(a) or 5(b) is due in accordance with its terms but for any reason is unavailable to or insufficient to hold harmless an indemnified party in respect to any losses, claims, damages, liabilities or expenses referred to therein, then each indemnifying party shall contribute to the aggregate losses, claims, damages, liabilities and expenses (including any investigation, legal and other expenses reasonably incurred in connection with, and any amount paid in settlement of, any action, suit or proceeding or any claims asserted, but after deducting any contribution received by any person entitled hereunder to contribution from any person who may be liable for contribution) incurred by such indemnified party, as incurred, in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Shares pursuant to this Agreement or, if such allocation is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to above but also the relative fault of the Company on the one hand and the Underwriters on the other hand in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses, as well as any other relevant equitable considerations. The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 6 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to above shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission. Notwithstanding the provisions of this Section 6, no Underwriter (except as may be provided in the Agreement Among Underwriters) shall be required to contribute any amount in excess of the underwriting discount applicable to the Shares purchased by such Underwriter hereunder. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. For purposes of this Section 6, each person, if any, who controls an Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act shall have the same rights to contribution as such Underwriter, and each director of the Company including any person who, with his or her consent, is named in the Registration Statement as about to become a director of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of the Section 15 of the Securities Act or Section 20 of the Exchange Act, shall have the same rights to contribution as the Company. Any party entitled to contribution will, promptly after receipt of notice of commencement of any action, suit or proceeding against such party in respect of which a claim for contribution may be made against another party or parties under this Section 6, notify such party or parties from whom contribution

may be sought, but the omission so to notify such party or parties from whom contribution may be sought shall not relieve the party or parties from whom contribution may be sought from any other obligation it or they may have hereunder or otherwise than under this Section 6. No party shall be liable for contribution with respect to any action, suit, proceeding or claim settled without its written consent. The Underwriter’s obligations to contribute pursuant to this Section 6 are several in proportion to their respective underwriting commitments and not joint.

(a) This Agreement may be terminated with respect to the Shares to be purchased on a Closing Date by the Representatives by notifying the Company at any time at or before a Closing Date in the absolute discretion of the Representatives if: (i) there has occurred any material adverse change in the securities markets or any event, act or occurrence that has materially disrupted the securities markets or there shall be such a material adverse change in general financial, political or economic conditions or the effect of international conditions on the financial markets in the United States is such as to make it, in the judgment of the Representatives, inadvisable or impracticable to market the Shares or enforce contracts for the sale of the Shares; (ii) there has occurred any outbreak or material escalation of hostilities or other calamity or crisis the effect of which on the financial markets of the United States is such as to make it, in the judgment of the Representatives, inadvisable or impracticable to market the Shares or enforce contracts for the sale of the Shares; (iii) trading in the Shares or any securities of the Company has been suspended or materially limited by the Commission or trading generally on the New York Stock Exchange, Inc., the American Stock Exchange, Inc. or the Nasdaq National Market has been suspended or materially limited, or minimum or maximum ranges for prices for securities shall have been fixed, or maximum ranges for prices for securities have been required, by any of said exchanges or by such system or by order of the Commission, the NASD, or any other governmental or regulatory authority; or (iv) a banking moratorium has been declared by any state or Federal authority; or (v) in the judgment of the Representatives, there has been, since the time of execution of this Agreement or since the respective dates as of which information is given in the Prospectus, any material adverse change in the assets, properties, financial condition, or in the results of operations, business affairs or business prospects of the Company, whether or not arising in the ordinary course of business.

(b) If this Agreement is terminated pursuant to any of its provisions, the Company shall not have any liability to any Underwriter, and no Underwriter shall have any liability to the Company; provided, however, that in the event of any such termination, the Company agrees to indemnify and hold harmless the Underwriters from all expenses incident to the performance of the obligations of the Company under this Agreement, including all costs and expenses referred to in paragraph 4(b); and, provided further, if this Agreement is terminated by the Representatives or the Underwriters because of any failure, refusal or inability on the part of the Company to comply with the terms or to fulfill any of the conditions of this Agreement, the Company shall reimburse the Underwriters for all out-of-pocket expenses (including the fees and disbursements of their counsel) incurred by them in connection with the proposed purchase and sale of the Shares or in contemplation of performing their obligations hereunder. Notwithstanding anything in this Section 7(b) to the contrary, no Underwriter who shall have failed or refused to purchase the Shares agreed to be purchased by it under this Agreement shall be relieved of liability to the Company or the other Underwriters for damages occasioned by its refusal.

8. Substitution of Underwriters. If any Underwriter shall default in its obligation to purchase on any Closing Date the Shares agreed to be purchased hereunder on such Closing Date, the Representatives shall have the right, within 36 hours thereafter, to make arrangements for one or more of the non-defaulting Underwriters, or any other underwriters, to purchase such Shares on the terms contained herein. If, however, the Representatives shall not have completed such arrangements within such 36-hour period, then the Company shall be entitled to a further period of 36 hours within which to procure another party or other parties satisfactory to the Underwriters to purchase such Shares on such terms. If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by the Representatives and the Company as provided above, the aggregate number of Shares which remains unpurchased on such Closing Date does not exceed 10% of the aggregate number of all the Shares that all the Underwriters are obligated to purchase on such date, then the Company shall have the right to require each non-defaulting Underwriter to purchase the number of Shares which such Underwriter agreed to purchase hereunder at such date and, in addition, to require each non-defaulting Underwriter to purchase its pro rata share (based on the number of Shares which such Underwriter agreed to purchase hereunder) of the Shares of such defaulting Underwriter or Underwriters for which such arrangements have not been made; provided nothing herein shall relieve a defaulting Underwriter from liability for its default. In any such case, either the Representatives or the Company shall have the right to postpone the applicable Closing Date for a period of not more than seven days in order to effect any necessary changes and arrangements (including any necessary amendments or supplements to the Registration Statement or Prospectus or any other documents), and the Company agrees to file promptly any

amendments to the Registration Statement or the Prospectus which in the opinion of the Company and the Underwriters and their counsel may thereby be made necessary.

If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by the Representatives and the Company as provided above, the aggregate number of such Shares which remains unpurchased exceeds 10% of the aggregate number of all the Shares to be purchased at such date, then this Agreement, or, with respect to a Closing Date which occurs after the Firm Shares Closing Date, the obligations of the Underwriters to purchase and of the Company to sell the Option Shares to be purchased and sold on such date, shall terminate, without liability on the part of any non-defaulting Underwriter to the Company, and without liability on the part of the Company, except as provided in Sections 4(b), 5, 6 and 7. The provisions of this Section 8 shall not in any way affect the liability of any defaulting Underwriter to the Company or the non-defaulting Underwriters arising out of such default. The term “Underwriter” as used in this Agreement shall include any person substituted under this Section 8 with like effect as if such person had originally been a party to this Agreement with respect to such Shares.

9. Miscellaneous. The respective agreements, representations, warranties, indemnities and other statements of the Company and the several Underwriters, as set forth in this Agreement or made by or on behalf of them pursuant to this Agreement, shall remain in full force and effect, regardless of any investigation (or any statement as to the results thereof) made by or on behalf of any Underwriter or the Company or any of their respective officers, directors or controlling persons referred to in Sections 5 and 6 hereof, and shall survive delivery of and payment for the Shares. In addition, the provisions of Sections 4(b), 5, 6 and 7 shall survive the termination or cancellation of this Agreement.

This Agreement has been and is made for the benefit of the Underwriters, the Company and their respective successors and assigns, and, to the extent expressed herein, for the benefit of persons controlling any of the Underwriters, or the Company, and directors and officers of the Company, and their respective successors and assigns, and no other person shall acquire or have any right under or by virtue of this Agreement. The term “successors and assigns” shall not include any purchaser of Shares from any Underwriter merely because of such purchase.

All notices and communications hereunder shall be in writing and mailed or delivered or by telephone or telegraph if subsequently confirmed in writing, (a) if to the Representatives, c/o Lazard Capital Markets LLC, 30 Rockefeller Center, New York, NY 10020 Attention: David G. McMillan, Jr. and Robert Lagay, with a copy to Morgan, Lewis & Bockius, LLP, 101 Park Avenue, New York, New York 10178 Attention: David W. Pollak, Esq. and (b) if to the Company, to Hemosense, Inc., 651 River Oaks Parkway, San Jose, California 95134, Attention: James Merselis, President and Chief Executive Officer, with a copy to Wilson, Sonsini, Goodrich & Rosati, P.C., 650 Page Mill Road, Palo Alto, California 94304 Attention: Michael J. Danaher and David J. Saul.

This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without regard to conflicts of law principles thereof. The Company and the Underwriters agree to waive trial by jury in any action, proceeding or

counterclaim brought by or on behalf of either party with respect to any matter whatsoever relating to or arising out of this Agreement or the purchase of the Shares hereunder.

This Agreement may be signed in any number of counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.


Very truly yours,

HEMOSENSE, INC.

By:
		Name:
		Title:


Name		Number of Firm Shares to Be Purchased
Lazard Capital Markets LLC
W.R. Hambrecht + Co., LLC
Roth Capital Partners, LLC

	Total