SC TO-T/A

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE TO

Amendment No. 4

TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)

OF THE SECURITIES EXCHANGE ACT OF 1934

Biosite Incorporated

(Name of Subject Company (Issuer))

Beckman Coulter, Inc.

Louisiana Acquisition Sub, Inc.

(Names of Filing Persons (Offerors))

Common Stock, par value $0.01 per share	090945 10 6
(Titles of Classes of Securities)	(CUSIP Number of Class of Securities)

Scott Garrett

President & CEO

Beckman Coulter, Inc.

4300 N. Harbor Boulevard

Fullerton, California 92834-3100

(714) 871-4848

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications on Behalf of the Filing Persons)

Copies to:

Paul D. Tosetti, Esq.

Cary K. Hyden, Esq.

Jonn R. Beeson, Esq.

Latham & Watkins LLP

633 West Fifth St., Suite 4000

Los Angeles, California 90071-2007

Tel: (213) 485-1234

CALCULATION OF FILING FEE

Transaction Valuation*	Amount of Filing Fee**
$1,758,341,280	$53,982

* Estimated for purposes of calculating the filing fee only. This amount assumes the purchase of up to 20,686,368 shares of common stock, par value $0.01 per share, of Biosite, including the associated preferred share purchase rights, at a purchase price of $85 per share. Such number of shares consists of (i) 16,000,118 shares of common stock issued and outstanding as of March 22, 2007, and (ii) 4,686,250 shares of common stock that are expected to be issuable before the expiration of the Offer under stock options and other rights to acquire Biosite shares.

** The amount of the filing fee, calculated in accordance with Rule 0-11 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), equals 0.0000307 of the transaction valuation.

x Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:	$53,982	Filing Party:	Beckman Coulter, Inc. and Louisiana Acquisition Sub, Inc.
Form or Registration No.:	Schedule TO-T	Date Filed:	April 2, 2007

¨ Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

x third-party tender offer subject to Rule 14d-1.

¨ issuer tender offer subject to Rule 13e-4.

¨ going-private transaction subject to Rule 13e-3.

¨ amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer:  ¨

AMENDMENT NO. 4 TO SCHEDULE TO

This Amendment No. 4 (this “Amendment”) amends and supplements the Tender Offer Statement on Schedule TO (the “Statement”), originally filed with the Securities and Exchange Commission (the “SEC”) on April 2, 2007 as amended by Amendments No. 1 through 3 to the Statement filed with the SEC by (i) Beckman Coulter, Inc., a Delaware corporation (“Beckman”), and (ii) Louisiana Acquisition Sub, Inc., a Delaware corporation (the “Purchaser”) and a wholly-owned subsidiary of Beckman. The Statement, as amended, relates to the offer by the Purchaser to purchase all issued and outstanding shares of common stock, par value $0.01 per share, together with the associated rights to purchase series A participating preferred stock, par value $0.01 per share (collectively, the “Shares” and each, a “Share”), of Biosite Incorporated, a Delaware corporation (“Biosite”), at a price of $85.00 per Share in cash, without interest (the “Offer Price”), less any applicable withholding taxes, upon the terms and subject to the conditions set forth in the Offer to Purchase and in the related Letter of Transmittal (which, together with any amendments or supplements thereto, collectively constitute the “Offer”). Capitalized terms used and not otherwise defined in this Amendment shall have the meanings assigned to such terms in the Offer to Purchase or in the Statement.

Items 1, 4 and 11 of the Statement, to the extent such Items incorporate by reference the information contained in the Offer, are hereby amended and supplemented as follows:

The “Summary Term Sheet” of the Offer to Purchase is hereby amended by replacing the paragraph under the subsection captioned “Are there any compensation arrangements between Beckman and Biosite’s executive officers or other key employees?” with the following three paragraphs and chart:

“ Neither Beckman nor Purchaser have proposed or agreed upon the terms of any employment compensation, severance or other employee benefits arrangements with Biosite’s executive officers. Also, neither Beckman nor the Purchaser expects to enter into any employment compensation, severance or other employee benefits arrangements with any of Biosite’s executive officers or other employees prior to completion of the merger of Purchaser with and into Biosite (the “Merger”).

Following completion of the Merger, Beckman expects to continue to employ Biosite’s employees, including its executive officers, on terms similar to their current employment arrangements, except that Beckman may provide benefits to Biosite’s employees under its benefit plans or Biosite’s benefit plans and that their bonus and severance arrangements will be replaced by Beckman’s standard arrangements, subject to certain exceptions. Following completion of the Merger, Beckman may also propose to modify the terms of the employment arrangements between Biosite and its current executive officers but does not plan to enter into employment agreements or arrangements, other than to continue those executives’ employment on an at will basis. See Section 13—“The Merger Agreement; Other Agreements.”

The Merger Agreement provides that each option to purchase Shares (a “Company Option”) outstanding immediately before the Merger is completed, including those held by Biosite’s executive officers, will become fully vested when the Merger is complete, subject to certain exceptions for employees on a leave of absence or for part-time employees. Each such Company Option will be assumed by Beckman and converted into a fully-vested and exercisable option to acquire shares of Beckman common stock (“Beckman Shares”), par value $0.10 per share (the “Assumed Option”). Each Assumed Option will have the same terms and conditions as the original Company Option, except that the exercise price and number of Beckman Shares subject to each Assumed Option will be adjusted to provide the same intrinsic value as the Company Option assumed. Based on the number of Company Options outstanding on March 22, 2007, once the Merger is completed, Biosite’s employees and directors will hold Assumed Options to purchase a maximum of 5,702,046 Beckman Shares, or 8.4% of the 61,851,303 Beckman Shares outstanding on March 31, 2007.

The “Summary Term Sheet” of the Offer to Purchase is hereby further amended by replacing the paragraph under the subsection captioned “What is the Top-Up Option and when could it be exercised?” with the following paragraph:

“ Biosite has granted Purchaser an option to purchase that number of newly-issued Shares that is equal to 10,000 shares more than the amount needed to give Purchaser ownership of 90% of the outstanding Shares (after giving effect to the Shares issued upon the exercise of such option) (the “Top-Up Option”), provided that the number of Shares that may be issued pursuant to the Top-Up Option may not exceed 19.9% of the number of Shares outstanding as of March 24, 2007. The Top-Up Option is exercisable only if Beckman, we and its and our affiliates own at least 80% of the outstanding Shares prior to exercising the Top-Up Option and would hold 90% of the outstanding Shares after such exercise, and in no event can the Top-Up Option be exercised for a number of Shares in excess of Biosite’s authorized and unissued Shares. Purchaser will pay Biosite $85.00 for each Share acquired through the Top-Up Option. The purpose of the Top-Up Option is to permit us to complete the Merger without a special meeting of Biosite’s stockholders under the “short form” merger provisions of Delaware law. We expect to exercise the Top-Up Option, subject to the limitations set forth in the Merger Agreement, if we acquire less than 90% of the issued and

outstanding Shares in the Offer. Unless prohibited by law or the Merger Agreement, we may exercise the Top-Up Option, in whole but not in part, at any time after we first accept Shares for payment in the Offer and prior to completion of the Merger or termination of the Merger Agreement. We may also exercise the Top-Up Option one or multiple times following our initial exercise of the Top-Up Option, subject to the same limitations that apply to our initial exercise. Following our initial exercise of the Top-Up Option, if any, and subject to the same terms and conditions, we expect to again exercise the Top-Up Option if our percentage ownership of the outstanding Shares falls below 90%, which could occur if Company Options are exercised following our initial or any subsequent exercise of the Top-Up Option. See Section 13—”The Merger Agreement; Other Agreements” for a more detailed description of the Top-Up Option.”

Items 3, 4, 5, 8 and 11 of the Statement, to the extent such Items incorporate by reference the information contained in the Offer, are hereby amended and supplemented as follows:

Section 8—”Certain Information Concerning Biosite” of the Offer to Purchase is hereby amended and supplemented by adding the following paragraphs at the end of the section:

“ Financial Analysis and Forecasts of Biosite management

Prior to entering into the Merger Agreement, representatives of Beckman and the Purchaser conducted a due diligence review of Biosite. In connection with this review, in March 2007, Biosite provided Beckman and the Purchaser certain preliminary projections of Biosite’s anticipated operating performance. Biosite advised Beckman and the Purchaser of certain assumptions, risks and limitations relating to these forecasts, as described below. These forecasts supplemented and provided greater detail than the financial forecasts of Biosite’s expected performance in 2007 that Biosite announced in a press release dated January 30, 2007. In that press release, Biosite indicated that it had established a 2007 total revenue target of $326 million and a 2007 GAAP diluted earnings per share target of $2.33.

Biosite provided Beckman and the Purchaser with certain “base case” internal financial analyses and forecasts for Biosite that had been prepared by Biosite’s management. Biosite has advised Beckman and Purchaser that:

• the “base case” forecasts were arrived at using various assumptions regarding market growth, market share, average sales prices, distributor discounts, geographic scope and applicable tax rates;

• revenue growth estimates were based on Biosite’s currently marketed products as well as its development-stage or pipeline products, with pipeline products weighted by their expected probability of success;

• the “base case” forecasts incorporate various assumptions regarding the timing of commercial launch of pipeline products, product utilization rates, product pricing and market penetration, and price erosion, among other factors.

The “base case” forecasts consisted of the following (in millions, except for earnings per share (“EPS”) amounts; A-Actual; E-Estimated):

	2005A		2006E		2007E		2008E		2009E		2010E		2011E		2012E		2013E		2014E		2015E
Total Revenues	$	287.7	$	308.5	$	325.4	$	358.9	$	420.1	$	507.2	$	637.0	$	782.9	$	969.0	$	1,191.0	$	1,437.1
COGS		85.1		91.5		97.9		100.0		106.0		118.3		139.7		166.0		204.6		241.5		284.2
Gross Profit on Product Sales	$	197.7	$	211.7	$	222.5	$	253.0	$	307.3	$	380.4	$	483.6	$	595.0	$	736.2	$	914.9	$	1,111.5
SG&A		76.7		85.1		90.4		98.7		114.7		134.4		165.6		203.5		251.9		309.7		373.6
R&D		42.2		46.0		52.5		55.6		60.9		68.5		79.6		78.3		77.5		95.3		115.0
Operating Profit	$	83.6	$	85.9	$	84.5	$	104.6	$	138.5	$	186.0	$	252.1	$	335.0	$	434.9	$	544.5	$	664.3
Interest/Other Income		2.7		4.2		2.2		5.1		7.6		11.7		16.8		21.2		25.7		29.1		31.8
Taxes		32.3		32.5		32.9		41.7		55.5		75.1		102.2		135.4		175.0		218.0		264.5
Net Income	$	54.0	$	57.6	$	53.9	$	68.0	$	90.6	$	122.6	$	166.7	$	220.9	$	285.6	$	355.7	$	431.6
EPS	$	2.92	$	3.21	$	3.19	$	3.93	$	5.11	$	6.74	$	8.95	$	11.57	$	14.59	$	17.73	$	20.98

Although Beckman and the Purchaser were provided with the foregoing forecasts, they did not base their analysis of Biosite solely on such forecasts.

In addition to the “base case” forecasts, Biosite provided Beckman and the Purchaser with a set of “upside scenario” forecasts involving several adjustments to the “base case” assumptions, consisting primarily of higher probabilities of success for pipeline products, expedited regulatory approvals for pipeline products, lower price erosion levels and higher market share assumptions. Beckman and the Purchaser believed that the “base case” forecasts reflected the most reliable estimate of Biosite’s future financial performance. Neither Beckman nor the Purchaser based their analysis of Biosite on these “upside scenario” forecasts.

Cautionary Information Relating to Forecasts

Biosite has advised Beckman and the Purchaser that the forecasts were not prepared with a view to public disclosure or compliance with the published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants regarding projections or forecasts. Furthermore, the forecasts do not necessarily reflect Biosite’s actual performance, nor do they reflect changes in Biosite’s business or changes in the economy in general resulting from events which have occurred since the forecasts were prepared. The forecasts do not purport to present operations in accordance with U.S. generally accepted accounting principles, or “GAAP,” and Biosite’s independent auditors have not examined, compiled or otherwise applied procedures to the forecasts and accordingly assume no responsibility for them. Biosite has advised Beckman and the Purchaser that its internal financial forecasts (upon which the forecasts provided to Beckman and the Purchaser were based in part) are, in general, prepared solely for internal use and capital budgeting and other management decisions and are subjective in many respects and thus susceptible to interpretations and periodic revisions based on actual experience and business developments.

The forecasts are based upon numerous assumptions made by Biosite management, including Biosite’s ability to achieve strategic goals, objectives and targets over the applicable period. These assumptions involve judgments with respect to future economic, competitive and regulatory conditions, financial market conditions and future business decisions, all of which are difficult or impossible to predict accurately and many of which are beyond Biosite’s control and none of which were subject to approval by Beckman or the Purchaser. These forecasts do not give effect to the Offer or the Merger, or any alterations that Biosite’s management or board of directors may make to Biosite’s operations or strategy after the completion of the Offer. Accordingly, there can be no assurance that the assumptions made in preparing the forecasts will prove accurate or that any of the forecasts will be realized.

It is expected that there will be differences between actual and projected results, and actual results may be materially greater or less than those contained in the forecasts due to numerous risks and uncertainties, including, but not limited to:

• Biosite’s ability to obtain regulatory approvals and complete clinical and pre-market activities needed to launch new products and obtain market acceptance of any new products;

• the impact of competition from companies with greater capital and resources and the effects of consolidation of major competitors in the market for immunoassay testing;

• Biosite’s ability to obtain and enforce intellectual property rights in order to launch new products as anticipated;

• Biosite’s ability to make significant expenditures and financial commitments to expand its commercial operations outside the United States;

• Biosite’s ability to recruit and retain key employees as a result of these other risks and uncertainties; and

• other risks and uncertainties described in reports filed by Biosite with the SEC under the Exchange Act, including without limitation under the heading “Risk Factors” in Biosite’s Annual Report on Form 10-K for the fiscal year ended December 31, 2006.

All forecasts are forward-looking statements.

The inclusion of the forecasts in this Offer to Purchase should not be regarded as an indication that any of Beckman, the Purchaser, Biosite or their respective affiliates or representatives considered or consider the forecasts to be a reliable prediction of future events, and the forecasts should not be relied upon as such. None of Beckman, the Purchaser, Biosite or any of their respective affiliates or representatives has made or makes any representation to any person regarding the ultimate performance of Biosite compared to the information contained in the forecasts, and none of them undertakes any obligation to update or otherwise revise or reconcile the forecasts to reflect circumstances existing after the date such forecasts were generated or to reflect the occurrence of future events even in the event that any or all of the assumptions underlying the forecasts are shown to be in error.

Stockholders are cautioned not to place undue reliance on the forecasts included in this Offer to Purchase.”

Items 4 and 11 of the Statement, to the extent such Items incorporate by reference the information contained in the Offer, are hereby amended and supplemented as follows:

Section 14—”Conditions of the Offer” of the Offer to Purchase is hereby amended and revised by replacing the lead in to the bullet point conditions of the offer with the following:

“ The Purchaser is required to accept for payment and pay for any tendered Shares pursuant to the Offer only if, at the Expiration Time:”

In addition, the fifth bullet point is hereby amended to delete the first two words of that clause (“all of”).

Items 4 and 11 of the Statement, to the extent such Items incorporate by reference the information contained in the Offer, are hereby amended and supplemented as follows:

Section 15—”Certain Legal Matters” of the Offer to Purchase is hereby amended and supplemented by adding the following sentence after the second paragraph under the subsection captioned “Antitrust Matters”:

“On April 17, 2007, the waiting period required under the HSR Act expired without a request for additional information from the FTC with respect to the Offer and the Merger.”

Item 12 of the Statement is hereby amended and supplemented to include the following:

“(a)(5)(C) Press Release issued by Beckman Coulter, Inc. on April 17, 2007.”

SIGNATURES

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

LOUISIANA ACQUISITION SUB, INC.
By:	/s/ ARNOLD A. PINKSTON
Name:	Arnold A. Pinkston
Title:	Secretary
BECKMAN COULTER, INC.
By:	/s/ ARNOLD A. PINKSTON
Name:	Arnold A. Pinkston
Title:	Senior Vice President, General Counsel and Secretary

Date: April 17, 2007

INDEX TO EXHIBITS

(a)(1)(A)	Offer to Purchase, dated as of April 2, 2007.*
(a)(1)(B)	Letter of Transmittal.*
(a)(1)(C)	Notice of Guaranteed Delivery.*
(a)(1)(D)	Letter to Brokers, Dealers, Banks, Trust Companies and other Nominees.*
(a)(1)(E)	Letter to Clients for use by Brokers, Dealers, Banks, Trust Companies and other Nominees.*
(a)(1)(F)	Guidelines for Certification of Taxpayer Identification Number on Substitute Form W-9.*
(a)(1)(G)	Summary Advertisement published on April 2, 2007.*
(a)(5)(A)	Joint press release issued by Beckman Coulter, Inc. and Biosite Incorporated, dated March 25, 2007 (incorporated by reference to the Schedule TO-C filed by Beckman Coulter, Inc. on March 26, 2007).
(a)(5)(B)	PowerPoint presentation by Beckman Coulter, Inc. on March 26, 2007 (incorporated by reference to the Schedule TO-C filed by Beckman Coulter, Inc. on March 26, 2006).
(a)(5)(C)	Transcript of a conference call conducted by Beckman Coulter, Inc. on March 26, 2007 (incorporated by reference to Schedule TO-C filed by Beckman Coulter, Inc. on March 27, 2007).
(a)(5)(D)	Press Release issued by Beckman Coulter, Inc. on April 2, 2007 (incorporated by reference to the Schedule TO-C filed by Beckman Coulter, Inc. on April 2, 2007).
(a)(5)(E)	Press Release issued by Beckman Coulter, Inc. on April 2, 2007.*
(a)(5)(F)	Press Release issued by Beckman Coulter, Inc. on April 5, 2007.*
(a)(5)(G)	Letter from Beckman Coulter, Inc. to Biosite Incorporated’s board of directors dated April 5, 2007.*
(a)(5)(H)	Press Release issued by Beckman Coulter, Inc. on April 10, 2007.*
(a)(5)(I)	Letter from Beckman Coulter, Inc. to Biosite Incorporated dated April 10, 2007.*
(a)(5)(J)	Press Release issued by Beckman Coulter, Inc. on April 17, 2007.
(b)	Commitment Letter dated March 24, 2007 between Morgan Stanley Senior Funding Inc., Citigroup Global Markets, Inc., and Beckman Coulter, Inc. (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed by Beckman Coulter, Inc. on March 26, 2007).
(d)(1)	Agreement and Plan of Merger, dated as of March 24, 2007, by and among Beckman Coulter, Inc., the Purchaser and Biosite Incorporated (incorporated by reference to Exhibit 2.1 to the Current Report on Form 8-K filed by Beckman Coulter, Inc. on March 26, 2007).
(d)(2)	Tender and Stockholder Support Agreement, dated as of March 24, 2007, by and among Beckman Coulter, Inc., the Purchaser, Kim D. Blickenstaff and Rita Blickenstaff (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by Beckman Coulter, Inc. on March 26, 2007).
(d)(3)	Confidentiality Agreement, dated as of May 11, 2006, between Beckman Coulter, Inc. and Biosite Incorporated.*
(d)(4)	Amendment to Confidentiality Agreement, dated June 2, 2006, between Beckman Coulter, Inc. and Biosite Incorporated.*
(d)(5)	Non-Solicitation Agreement dated March 23, 2007 between Beckman Coulter, Inc. and Biosite Incorporated.*

* Previously filed

EX-99.(A)(5)(J)

Exhibit (a)(5)(J)

	FINAL
	NEWS RELEASE

Contact:	Robert Raynor	(714) 773-7620
	Director, Investor Relations

Beckman Coulter Proposed Acquisition of Biosite Passes Milestone with U.S. Regulatory Approval

FULLERTON, CA, April 17, 2007 – Beckman Coulter, Inc. (NYSE:BEC), a leading developer, manufacturer, and marketer of products that simplify, automate, and innovate complex biomedical testing, today announced that the mandatory waiting period associated with its proposed acquisition of Biosite^® Incorporated (NASDAQ: BSTE) under the Hart-Scott-Rodino Antitrust Improvement Act of 1976, as amended, has expired. The U.S. Federal Trade Commission did not request any additional information or documentary material.

Scott Garrett, Beckman Coulter President and Chief Executive Officer, said, “We are pleased to have achieved this significant milestone toward the completion of our acquisition of Biosite. Expiration of the waiting period without a second request for information further demonstrates the certainty of Beckman Coulter’s transaction with Biosite, and we remain on schedule to close the transaction by early May. We continue to be very enthusiastic about the prospects for developing Biosite and Beckman Coulter as a combined business.”

As announced on April 2, 2007, Louisiana Acquisition Sub, Inc., a wholly-owned subsidiary of Beckman Coulter, has commenced a tender offer for all outstanding shares of Biosite at a price of $85.00 per share in cash. The offer price represents an approximately 53.5% premium over Biosite’s closing stock price of $55.38 on March 23, 2007, the last trading day before the announcement of Beckman Coulter’s intention to make the offer pursuant to a definitive merger agreement between Beckman Coulter and Biosite. The Beckman Coulter tender offer is not subject to any financing conditions and is scheduled to be completed at 12:00 midnight, New York City time, on Friday, April 27, 2007 (the end of the day on Friday).

About Beckman Coulter

Beckman Coulter, Inc., based in Fullerton, California, develops, manufactures and markets products that simplify, automate, and innovate complex biomedical tests. More than 200,000 Beckman Coulter systems operate in laboratories around the world supplying critical information for improving patient health and reducing the cost of care. Recurring revenues consisting of supplies, test kits, service and operating-type lease payments represent more than 75 percent of the company’s 2006 annual sales of $2.5 billion. For more information, visit www.beckmancoulter.com.

Forward Looking Statements

This press release contains forward-looking statements, including statements regarding the anticipated closing of Beckman’s tender offer. These statements are based on current expectations, forecasts and assumptions. Actual results could differ materially from those anticipated by these forward-looking statements as a result of a number of factors, some of which may be beyond Beckman Coulter’s control. Among other things, these factors include the risk that the acquisition will not be completed because the tender offer did not proceed as anticipated or closing conditions to the acquisition were not satisfied. For a further list and description of risks and uncertainties associated with Beckman Coulter’s and Biosite’s businesses, see their reports filed with the Securities and Exchange Commission, including each company’s “Risk Factors” section in its most recent annual report on Form 10-K filed with the Securities and Exchange Commission. Beckman Coulter disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

Additional Information and Where to Find It

This announcement is neither an offer to purchase nor a solicitation of an offer to sell shares of Biosite. Stockholders of Biosite are urged to read the tender offer materials described below because they contain important information that stockholders should consider before making any decision regarding tendering their shares. The tender offer is being made pursuant to a Tender Offer Statement on Schedule TO (including the Offer to Purchase, the related Letter of Transmittal and other tender offer materials) filed by Beckman and Louisiana Acquisition Sub with the SEC on April 2, 2007, as amended. In addition, on April 2, 2007, Biosite filed a Solicitation/Recommendation Statement on Schedule 14D-9 with the SEC related to the tender offer. The tender offer materials contain important information, which should be read carefully before any decision is made with respect to the tender offer. The Offer to Purchase, the related Letter of Transmittal and certain other offer documents, as well as the Solicitation/Recommendation Statement, are available free of charge on the SEC’s website (www.sec.gov) or from D.F. King & Co., Inc., the information agent for the tender offer, at (800) 769-4414 (toll free). American Stock Transfer & Trust Company is acting as depositary for the tender offer. The dealer manager for the offer is Morgan Stanley.

In addition to the Offer to Purchase, the related Letter of Transmittal and certain other offer documents, as well as the Solicitation/Recommendation Statement, Beckman Coulter and Biosite file annual, quarterly and special reports, proxy statements and other information with the SEC. You may read and copy any reports, statements or other information filed by Beckman Coulter and Biosite at the SEC public reference room at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the public reference room. Beckman Coulter’s and Biosite’s filings with the SEC are also available to the public from commercial document-retrieval services and the SEC’s website.

CORRESP

	650 Town Center Drive, 20th Floor
	Costa Mesa, California 92626-1925
	Tel: (714) 540-1235 Fax: (714) 755-8290
	www.lw.com
	FIRM / AFFILIATE OFFICES
	Barcelona	New Jersey
	Brussels	New York
	Chicago	Northern Virginia
	Frankfurt	Orange County
April 17, 2007	Hamburg	Paris
	Hong Kong	San Diego
	London	San Francisco
	Los Angeles	Shanghai
	Madrid	Silicon Valley
	Milan	Singapore
Christina Chalk, Special Counsel	Moscow	Tokyo
Securities and Exchange Commission	Munich	Washington, D.C
Division of Corporate Finance
Office of Mergers and Acquisitions	File No. 006728-0155
100 F Street, NE
Washington, D.C. 20549

Re: Biosite, Inc.

Schedule TO-T filed on April 2, 2007 by Beckman Coulter, Inc.

and Louisiana Acquisition Sub, Inc.

Schedule TO-T/A filed on April 5, 2007

Schedule TO-T/A filed on April 9, 2007

Schedule TO-T/A filed on April 10, 2007

SEC File No. 5-50351

Dear Ms. Chalk:

We hereby respond on behalf of Beckman Coulter, Inc. (“Beckman”) and Louisiana Acquisition Sub, Inc. (the “Purchaser”) to the comments of the staff (the “Staff”) of the Securities and Exchange Commission (the “Commission”), as set forth in the Staff’s letter of comment dated April 10, 2007 (the “Comment Letter”), to the above referenced Schedule TO-T, as amended. Beckman and the Purchaser are simultaneously filing via EDGAR this letter (tagged as correspondence) and Amendment No. 4 to the Schedule TO-T (“Amendment No. 4”). For your convenience, we have also attached a copy of Amendment No. 4 in the traditional, non-EDGAR format, to this letter.

Beckman and the Purchaser have the following responses to the Staff’s comments in the Comment Letter. For your convenience, each response corresponds to the comment that immediately precedes it, each of which has been reproduced from the Comment Letter in the order presented.

Schedule TO-T – Exhibit (a)(1)(A) – Offer to Purchase dated April 2, 2007.

1. Summary Term Sheet – Are there any compensation arrangements between Beckman and Biosite’s executive officers or other key employees? Page 2: You disclose that Beckman and Biosite have not yet agreed upon the terms of compensation and benefit plan equity awards for affiliates of Beckman, but are continuing to discuss those arrangements. Please generally describe the parameters of the possible

April 17, 2007

Page 2

arrangements with Biosite affiliates with respect to their continued affiliation with the Company after the merger. In particular, indicate the upper end of their total equity participation in the continuing entity. We may have additional comments after reviewing your response.

Response: We have revised the disclosure referenced in the comment above in response to the Staff’s comment.

2. What is the Top Up Option and when could it be exercised? Page 5: Please clarify how and why the Top-Up Option could be exercised multiple times, or “re-exercised,” as you state at the bottom on page 5.

Response: We have revised the disclosure referenced in the comment above in response to the Staff’s comment.

3. Background of the Offer; Past Contacts, Negotiations and Transactions, Page 26: Throughout this section, you refer to confidential forecasts and projections provided to Beckman’s representatives by Biosite during the course of the negotiations resulting in this tender offer. All non-public financial forecasts and projections provided by Biosite to Beckman and resulting in this offer must be disclosed in the Offer to Purchase. In addition, please disclose the material assumptions upon which such projected figures are based.

Response: We have revised the disclosure referenced in the comment above in response to the Staff’s comment.

4. Background of the Offer; Past Contacts, Negotiations and Transactions, Page 26: During the negotiations leading up to this tender offer, Beckman several times proposed to acquire Biosite for consideration consisting in whole or in part of stock. However, in this offer, you are making an all-cash offer. Please advise why the terms of the transaction changed in this manner.

Response: We supplementally advise the Staff that Beckman’s initially proposed transactions to acquire Biosite provided for a combination of cash and stock consideration, with the maximum amount of cash issuable in each proposed transaction being limited to a level designed to allow the transaction to constitute a reorganization for federal income tax purposes. Beckman believed these proposed transaction structures would be attractive to Biosite stockholders with a low tax basis in their Biosite stock because those stockholders could elect to receive a portion of the consideration in the form of stock and defer some of the taxes that would otherwise be payable on their gains realized in connection with the transaction. However, because Beckman believed that its stock was undervalued by the stock market, in calculating Beckman’s cost to effect the transaction, Beckman placed a greater value on the stock portion of the consideration than would be implied by the trading price of its stock. Accordingly, Beckman revised its proposal to provide for an all cash offer at a higher price per share of Biosite common stock, which was then accepted by Biosite’s board of directors.

April 17, 2007

Page 3

5. Conditions of the Offer, Page 50: All offer conditions, other than conditions related to regulatory approvals necessary for consummation of the offer, must be satisfied or waived as of the expiration of the offer. Revise this section to clarify that all of the listed offer conditions will be judged as of expiration.

Response: We have revised the disclosure referenced in the comment above in response to the Staff’s comment.

Schedule TO-T/A filed on April 9, 2007

6. We note the assertions in the letter dated April 5, 2007 filed as an exhibit to Amendment 2 to the Schedule TO-T. In that letter to Biosite, you assert that Biosite is prohibited from responding to Inverness’ request for additional information under the terms of the merger agreement. You further note that responding in violation of the merger agreement would put Biosite in the position of breaching Section 5.3 of the agreement and “could ultimately prevent Biosite from being able to terminate the merger agreement to accept an alternative transaction.” You further state that if Biosite responds to Inverness’s inquiries, “Beckman would potentially also have the right to terminate the merger agreement and receive a $50 million termination fee from Biosite . . .” which fee “will come out of Biosite’s stockholders’ pockets.” Today Biosite issued a press release entitled “Biosite Prepared to Engage in Negotiations with Inverness Medical Innovations.” The press release indicates that the Biosite Board has authorized the company to “engage and participate in” negotiations with Inverness, which may include providing non-public financial information to Inverness. Given Beckman’s assertions in its letter dated April 5, 2007 and the apparent contradictory interpretation of the merger agreement by Biosite, advise how Beckman will proceed.

Response: Beckman has reserved its rights to enforce the terms of the Merger Agreement.

* * *

In making the responses above, we, on behalf of Beckman and the Purchaser, acknowledge that (i) Beckman and the Purchaser are responsible for the adequacy and accuracy of the disclosure in the Schedule TO-T; (ii) Staff comments or changes to disclosure in response to Staff comments do not foreclose the Commission from taking any action with respect to the Schedule TO-T; and (iii) neither Beckman nor the Purchaser may assert Staff comments as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

April 17, 2007

Page 4

Once you have had time to review our responses to the Staff’s comments and the corresponding changes in Amendment No. 4, we would appreciate the opportunity to discuss any additional questions or concerns that you may have. Please call Paul D. Tosetti at (213) 891-8770 or me at (714) 755-8212.

Sincerely,

/s/ Jonn R. Beeson

Jonn R. Beeson

of LATHAM & WATKINS LLP

Enclosures

cc: Paul D. Tosetti, Esq., Latham & Watkins LLP (via electronic mail)

Cary K. Hyden, Esq., Latham & Watkins LLP (via electronic mail)

Scott Garrett, Beckman Coulter, Inc. (via electronic mail)

Paul Glyer, Beckman Coulter, Inc. (via electronic mail)

Arnold Pinkston, Beckman Coulter, Inc. (via electronic mail)

Keith Flaum, Cooley Godward Kronish LLP (via electronic mail)