SC TO-T/A

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE TO

Amendment No. 3

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. 3 TO SCHEDULE TO

This Amendment No. 3 (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 Amendment No. 1 on April 5, 2007 and Amendment No. 2 on April 9, 2007, 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, relating 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.

Amendment to Offer to Purchase

Item 5 of the Statement, to the extent such Item incorporates by reference the information contained in the Offer is hereby amended and supplemented as follows:

Section 11—“Background of the Merger” of the Offer to Purchase is hereby amended and supplemented by adding the following paragraph at the end of the subsection captioned “Background of the Offer”:

“On April 9, 2007, Mr. Garrett sent a letter to Biosite’s board of directors again reaffirming Beckman’s commitment to acquire Biosite under the terms of the Merger Agreement, asserting that the April 4th letter from Inverness did not constitute an Acquisition Proposal (as defined below) and that the Inverness letter contemplates an offer that would not reasonably be likely to lead to a Superior Proposal (as defined below). Mr. Garrett’s letter highlighted the conditional nature of Inverness’ indication of interest in making an offer as well as its financing letters. On the following day, Beckman issued a press release making these same points public and waiving, in this instance, the 48 hour notice period that Biosite is required to provide Beckman under the Merger Agreement prior to engaging or participating in discussions or negotiations with, or furnishing any information to, Inverness or any of its representatives or financing sources. The press release was followed by a letter from Mr. Garrett to Mr. Blickenstaff formally waiving such 48 hour notice period.”

Miscellaneous

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

“(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.”

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 10, 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.
(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)(H)

Exhibit (a)(5)(H)

	NEWS RELEASE

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

Beckman Coulter Responds To Biosite Filing

FULLERTON, CA (April 10, 2007)—Beckman Coulter, Inc. (NYSE: BEC), a leading developer, manufacturer, and marketer of products that simplify, automate, and innovate complex biomedical testing, today responded to the decision by the Board of Directors of Biosite^® Incorporated (NASDAQ: BSTE) to authorize Biosite to engage and participate in discussions and negotiations with Inverness Medical Innovations, Incorporated (AMEX: IMA).

Scott Garrett, Beckman Coulter’s President and Chief Executive Officer, said, “The conditional and uncertain terms of the Inverness offer should give the Biosite board and its stockholders enormous pause. In our view, the fact that Inverness has not proposed a tender offer, which could be concluded relatively quickly, speaks volumes about the firmness of its financing. Inverness’ financing ‘commitments’ contain remarkably broad conditions and contingencies. It is not surprising, therefore, that Inverness instead is suggesting a one-step transaction – one that would take months to complete.”

Mr. Garrett further suggested that the Biosite Board should communicate the risks and uncertainties of the Inverness offer to Biosite’s stockholders who, based on trading levels in the marketplace, may be unaware of these risks.

“We remain committed to our transaction with Biosite and continue to be very enthusiastic about the prospects for developing Biosite and Beckman Coulter as a combined business,” stated Mr. Garrett. “Given the significant contingencies and uncertainties associated with Inverness’ proposal and the superiority of the transaction offered by Beckman Coulter’s definitive merger agreement with Biosite, Beckman Coulter is waiving the requirement that Biosite provide Beckman Coulter 48 hours notice prior to engaging in discussions or negotiations with or furnishing non-public information to Inverness.”

“We believe Biosite stockholders will conclude that Inverness is unable to make an offer for Biosite that is as compelling as the definitive transaction between Beckman Coulter and Biosite which is scheduled to be completed within the next 25 days. By waiving this 48-hour notice period, we are seeking to resolve the uncertainty in the marketplace resulting from Inverness’ offer as quickly as possible,” concluded Mr. Garrett.

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 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 and interpretation of the merger agreement between Beckman Coulter and Biosite. 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, closing conditions to the acquisition were not satisfied or the risk that the merger agreement will be interpreted differently. 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. 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.

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

Exhibit (a)(5)(I)

April 10, 2007

Mr. Kim D. Blickenstaff

Chief Executive Officer

Biosite Incorporated

9975 Summers Ridge Road

San Diego, CA 92121

Dear Kim:

I am disappointed that the Board of Directors of Biosite Incorporated (“Biosite’) has made a determination that the letter provided by Inverness Medical Innovations, Inc. (“Inverness”) to Biosite on April 4, 2007 constitutes an “Acquisition Proposal” reasonably likely to lead to a “Superior Proposal” (as such terms are defined in the Agreement and Plan of Merger dated as of March 24, 2007 (the “Merger Agreement”), among Beckman Coulter, Inc. (“Beckman”), Louisiana Acquisition Sub, Inc., and Biosite). Capitalized terms used and not otherwise defined in this letter shall have the meanings ascribed to such terms in the Merger Agreement.

Given our confidence that Inverness is not able to offer a competing transaction that is superior to the Merger Agreement, we would strongly prefer that the discussions between Biosite and Inverness be concluded as quickly as possible. We believe that this will allow Biosite’s stockholders adequate time in advance of the expiration of Beckman’s tender offer to reach the same conclusion and tender into Beckman’s offer.

To that end, without waiving Beckman’s other rights under the Merger Agreement (including, without limitation, Beckman’s right to claim that the Inverness letter constituted neither an “Acquisition Proposal” nor something that would reasonably be likely to lead to a “Superior Proposal”), I am writing this letter on behalf of Beckman to waive, in this instance, the 48 hour notice period under Section 5.2 of the Merger Agreement that Biosite is required to provide Beckman prior to engaging or participating in discussions or negotiations with, or furnishing any information to, Inverness or any of its Representatives or financing sources.

Sincerely,

Scott Garrett

President and Chief Executive Officer

Beckman Coulter, Inc.

Beckman Coulter, Inc. Scott T. Garrett President and Chief Executive Officer Corporate Headquarters 4300 N. Harbor Boulevard P.O. Box 3100 Fullerton, CA 92834-3100 Telephone:  (714) 773-3583 Facsimile:     (714) 773-8543 E-mail:          stgarrett@beckman.com