EXHIBIT 10.1

TENDER AND STOCKHOLDER SUPPORT AGREEMENT

This TENDER AND STOCKHOLDER SUPPORT AGREEMENT (this “Agreement”), dated
March 24, 2007, is by and among: Beckman Coulter, Inc., a Delaware corporation
(“Parent”); Louisiana Acquisition Sub, Inc., a Delaware corporation and a wholly
owned subsidiary of Parent (“Purchaser”); and Kim D. Blickenstaff and Rita
Blickenstaff (the “Stockholder”), a stockholder of Biosite Incorporated, a
Delaware corporation (the “Company”).

WHEREAS, Parent, Purchaser and the Company propose to enter into an Agreement
and Plan of Merger, dated as of the date hereof (the “Merger Agreement”), which
provides, among other things, for Purchaser to conduct a tender offer for all of
the issued and outstanding Company Shares (as defined below) of the Company (the
“Offer”) and the merger of Purchaser with and into the Company, with the Company
continuing as the surviving corporation (the “Merger”), upon the terms and
subject to the conditions set forth in the Merger Agreement (capitalized terms
used herein without definition shall have the respective meanings specified in
the Merger Agreement);

WHEREAS, the Stockholder owns 241,946 issued and outstanding shares of common
stock, par value $0.001 per share, of the Company (the “Company Shares”) (such
Company Shares, together with any other issued and outstanding shares of capital
stock of the Company acquired by the Stockholder after the date hereof and prior
to the earlier of the Effective Time and the termination of all of the
Stockholder’s obligations under this Agreement, including any Company Shares
acquired by means of purchase, dividend or distribution, or issued upon the
exercise of any warrants or options, or the conversion of any convertible
securities or otherwise, being collectively referred to herein as the “Shares”);
and

WHEREAS, as a condition to the willingness of Parent and Purchaser to enter into
the Merger Agreement and as an inducement and in consideration therefor, the
Stockholder has agreed to enter into this Agreement.

NOW, THEREFORE, in consideration of the foregoing and the mutual covenants and
agreements set forth herein and in the Merger Agreement, and intending to be
legally bound hereby, the parties hereto agree as follows:

SECTION 1. Representations and Warranties of the Stockholder. The Stockholder
hereby represents and warrants to Parent and Purchaser as follows:

(a) The Stockholder (i) is the record or beneficial owner, and has good and
marketable title to, the Shares, free and clear of any and all liens, claims,
security interests, proxies, voting trusts or agreements, options, rights,
understandings or arrangements or any other encumbrances whatsoever on title,
transfer, or exercise of any rights of a stockholder in respect of such Shares
(collectively, “Encumbrances”); (ii) does not own, of record or beneficially,
any shares of capital stock of the Company (or rights to acquire any such
shares) other than the Shares and other than Company Options to purchase up to
437,811 Company Shares); and (iii) has the sole right to vote, sole power

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of disposition, sole power to issue instructions with respect to the matters set
forth in Sections 3, 4, and 6 hereof, sole power of conversion, sole power to
demand appraisal rights and sole power to agree to all of the matters set forth
in this Agreement, in each case with respect to all of the Stockholder’s Shares,
with no material limitations qualification or restrictions on such rights,
subject to applicable federal securities law and the terms of this Agreement.

(b) The Stockholder has the legal capacity and all requisite power and authority
to execute and deliver this Agreement and to perform the Stockholder’s
obligations hereunder and consummate the transactions contemplated hereby. This
Agreement has been duly and validly executed and delivered by the Stockholder,
and constitutes a valid and binding obligation of the Stockholder enforceable in
accordance with its terms, subject to the effects of bankruptcy, insolvency,
fraudulent conveyance, reorganization, moratorium and other similar laws
relating to or affecting creditors’ rights generally and general equitable
principles (whether considered in a proceeding in equity or at law).

(c) The execution and delivery of this Agreement and the consummation by the
Stockholder of the transactions contemplated hereby will not (i) result in a
violation of, or a default under, or conflict with any contract, trust,
commitment, agreement, understanding, arrangement or restriction of any kind to
which the Stockholder is a party or by which the Stockholder or the
Stockholder’s assets are bound, or (ii) violate, or require any consent,
approval, or notice under, any provision of any judgment, order, decree,
statute, law, rule or regulation applicable to the Stockholder.

SECTION 2. Representations and Warranties of Parent and Purchaser. Each of
Parent and Purchaser hereby, jointly and severally, represents and warrants to
the Stockholder as follows:

(a) Each of Parent and Purchaser is a corporation duly organized, validly
existing and in good standing (with respect to jurisdictions which recognize
such concept) under the laws of the jurisdiction in which it is incorporated,
and each of Parent and Purchaser has all requisite corporate power and corporate
authority to execute and deliver this Agreement and to perform its obligations
hereunder and consummate the transactions contemplated hereby, and has taken all
necessary corporate action to authorize the execution, delivery and performance
of this Agreement.

(b) This Agreement has been duly authorized, executed and delivered by each of
Parent and Purchaser, and constitutes a valid and binding obligation of Parent
and Purchaser enforceable in accordance with its terms, subject to the effects
of bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and
other similar laws relating to or affecting creditors’ rights generally and
general equitable principles (whether considered in a proceeding in equity or at
law).

(c) The execution and delivery of this Agreement and the consummation by Parent
and Purchaser of the transactions contemplated hereby will not (i) result in a
violation of, or a default under, or conflict with (x) any provisions of the

 

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organizational documents of Parent or Purchaser or (y) any contract, trust,
commitment, agreement, understanding, arrangement or restriction of any kind to
which such Parent or Purchaser is a party or by which Parent or Purchaser or
their assets are bound, or (ii) violate, or require any consent, approval, or
notice under, any provision of any judgment, order, decree, statute, law, rule
or regulation applicable to Parent or Purchaser.

SECTION 3. Tender of the Shares.

(a) Unless this Agreement shall have been terminated in accordance with its
terms, and subject to Section 4, the Stockholder hereby agrees that he shall
(i) tender (and deliver any certificates evidencing) his Shares, or cause his
Shares to be tendered, into the Offer promptly following the commencement of the
Offer, and in any event no later than the third business day prior to the
Initial Expiration Date, free and clear of all Encumbrances and (ii) not
withdraw his Shares, or cause his Shares to be withdrawn, from the Offer at any
time. Unless this Agreement shall have been terminated in accordance with its
terms, and subject to Section 4, if the Stockholder acquires Shares after the
date hereof, the Stockholder shall (i) tender or cause to be tendered such
Shares on or before the third business day prior to the Initial Expiration Date
or, if later, on or before the second business day after such acquisition but in
any event prior to the date of expiration of the Offer and (ii) not withdraw his
Shares, or cause his Shares to be withdrawn, from the Offer at any time.

(b) If the Offer is terminated or withdrawn by Purchaser, or the Merger
Agreement is terminated prior to the purchase of Shares in the Offer, Parent and
Purchaser shall promptly return, and shall cause any depository acting on behalf
of Parent and Purchaser to return all tendered Shares to the registered holders
of the Shares tendered in the Offer.

SECTION 4. Transfer of the Shares; Other Actions.

(a) Prior to the termination of this Agreement, except as otherwise provided
herein (including pursuant to Section 3 hereof), without prior written consent
of Parent or Purchaser, the Stockholder shall not: (a) transfer, assign, sell,
gift-over, pledge or otherwise dispose (whether by sale, merger, consolidation,
liquidation, dissolution, dividend, distribution or otherwise) of, or consent to
any of the foregoing (“Transfer”), any or all of the Shares or any right or
interest therein; (b) enter into any contract, option or other agreement,
arrangement or understanding with respect to any Transfer; (c) grant any proxy,
power-of-attorney or other authorization or consent with respect to any of the
Shares; (d) deposit any of the Shares into a voting trust, or enter into a
voting agreement or arrangement with respect to any of the Shares; or (e) take
any other action that would in any way restrict, limit or interfere with the
performance of the Stockholder’s obligations hereunder or the transactions
contemplated hereby.

SECTION 5. Certain Events. In the event of any stock split, stock dividend,
merger, reorganization, recapitalization or other change in the capital
structure of the Company affecting the Company Shares or the acquisition of
additional Company Shares or other securities or rights of the Company by the
Stockholder, the number of Shares shall be adjusted appropriately, and this
Agreement and the rights and obligations hereunder shall attach to any
additional Company Shares or other securities or rights of the Company issued to
or acquired by the Stockholder.

 

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SECTION 6. Covenant to Vote. Unless this Agreement shall have been terminated in
accordance with its terms, the Stockholder hereby agrees to vote all Shares
beneficially owned or controlled by the Stockholder (the “Vote Shares”), or to
grant a consent or approval in respect of the Vote Shares, in connection with
any meeting of the shareholders of the Company or any action by written consent
in lieu of a meeting of shareholders of the Company (i) in favor of the Merger
or any other transaction pursuant to which Parent proposes to acquire the
Company, whether by tender offer, merger, or otherwise, in which stockholders of
the Company would receive consideration per share of Company Shares equal to or
greater than the consideration to be received by such stockholders in the Offer
and the Merger, and/or (ii) against any action or agreement which would impede,
interfere with or prevent the Merger, including, but not limited to, any other
extraordinary corporate transaction, including, a merger, acquisition, sale,
consolidation, reorganization or liquidation involving the Company and a third
party, or any other proposal of a third party to acquire the Company or all or
substantially all of the assets thereof.

SECTION 7. Further Assurances. The Stockholder shall, upon request of Parent or
Purchaser, execute and deliver any additional documents and take such further
actions as may reasonably be deemed by Parent or Purchaser to be necessary or
desirable to carry out the provisions of this Agreement.

SECTION 8. Termination. This Agreement, and all rights and obligations of the
parties hereunder, shall terminate on the earlier of: (a) the date the Merger
Agreement is terminated in accordance with its terms; and (b) the Effective
Time; provided, however, that (i) nothing herein shall relieve any party from
liability for any breach hereof; and (ii) Section 10 and Section 11 shall
survive any termination of this Agreement.

SECTION 9. Waiver of Appraisal and Dissenter’s Rights. The Stockholder waives
and agrees not to exercise any rights of appraisal or rights to dissent from the
Merger that the Stockholder may have with respect to the Stockholder’s Shares.

SECTION 10. Expenses. All fees, costs and expenses incurred in connection with
this Agreement and the transactions contemplated hereby shall be paid by the
party incurring such fees, costs and expenses.

SECTION 11. Miscellaneous.

(a) Notices. All notices and other communications hereunder shall be in writing
and shall be deemed given if delivered personally, telecopied (which is
confirmed) or sent by a nationally recognized overnight courier service, such as
Fedex (providing proof of delivery), to the parties at the following addresses
(or at such other address for a party as shall be specified by like notice):

 

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If to the Stockholder:

Kim D. Blickenstaff

Biosite Incorporated

9975 Summers Ridge Road

San Diego, CA 92121

Facsimile:    (858) 695-9853

with a copy to:

Biosite Incorporated

9975 Summers Ridge Road

San Diego, CA 92121

Attention:    David B. Berger, Vice President, Legal Affairs

Facsimile:   (858) 695-9853

and a copy to:

Cooley Godward Kronish LLP

4401 Eastgate Mall

San Diego, CA

92121-1909

Attention:    Fred Muto, Esq.

Facsimile:   (858) 550-6420

If to Parent or Purchaser, to:

Beckman Coulter, Inc.

4300 N. Harbor Boulevard

P.O. Box 3100

Fullerton, CA 92834-3100 USA

Attention:    General Counsel

Facsimile:   (714) 773-7936

with a copy to:

Latham & Watkins LLP

633 West Fifth St., Suite 4000

Los Angeles, CA 90071-2007

Attention:    Paul D. Tosetti, Esq.

                     Cary K. Hyden, Esq.

                     Jonn R. Beeson, Esq.

Facsimile:   (213) 891-8763

(b) Headings. The headings contained in this Agreement are for reference
purposes only and shall not affect in any way the meaning or interpretation of
this Agreement.

 

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(c) Counterparts. This Agreement may be executed manually or by facsimile by the
parties hereto in any number of counterparts, each of which shall be considered
one and the same agreement and shall become effective when a counterpart hereof
shall have been signed by each of the parties and delivered to the other
parties.

(d) Entire Agreement. This Agreement (together with the Merger Agreement and any
other documents and instruments referred to herein and therein) constitutes the
entire agreement among the parties with respect to the subject matter hereof and
thereof and supersedes all other prior agreements and understandings, both
written and oral, among the parties or any of them with respect to the subject
matter hereof and thereof. This Agreement is not intended and does not confer
upon any Person other than the parties hereto any rights hereunder.

(e) Governing Law. This Agreement shall be governed by and construed in
accordance with the laws of the State of Delaware, without giving effect to the
principles of conflicts of law thereof.

(f) Assignment. Neither this Agreement nor any of the rights, interests or
obligations hereunder shall be assigned by any of the parties hereto (whether by
operation of law or otherwise) without the prior written consent of the other
parties except that Parent and Purchaser may assign, in their sole discretion
and without the consent of any other party, any or all of their rights,
interests and obligations hereunder to each other or to one or more direct or
indirect wholly-owned subsidiaries of Parent (each, an “Assignee”). Any such
Assignee may thereafter assign, in its sole discretion and without the consent
of any other party, any or all of its rights, interests and obligations
hereunder to one or more additional Assignees. Subject to the preceding
sentence, this Agreement will be binding upon, inure to the benefit of and be
enforceable by, the parties and their respective successors and assigns, and the
provisions of this Agreement are not intended to confer upon any person other
than the parties hereto any rights or remedies hereunder.

(g) Severability of Provisions. If any term or provision of this Agreement is
invalid, illegal or incapable of being enforced by rule of law or public policy,
all other conditions and provisions of this Agreement shall nevertheless remain
in full force and effect so long as the economic or legal substance of the
transactions contemplated by this Agreement is not affected in any manner
adverse to any party. Upon such determination that any term or other provision
is invalid, illegal or incapable of being enforced, the parties hereto shall
negotiate in good faith to modify this Agreement so as to effect the original
intent of the parties as closely as possible in an acceptable manner to the end
that the transactions are fulfilled to the extent possible.

(h) Specific Performance. The parties hereto acknowledge that money damages
would be an inadequate remedy for any breach of this Agreement by any party
hereto, and that the obligations of the parties hereto shall be enforceable by
any party hereto through injunctive or other equitable relief.

 

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(i) Amendment. No amendment, modification or waiver in respect of this Agreement
shall be effective against any party unless it shall be in writing and signed by
such party.

(j) Binding Nature. This Agreement is binding upon and is solely for the benefit
of the parties hereto and their respective successors, legal representatives and
assigns.

[signature page follows]

 

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IN WITNESS WHEREOF, Parent, Purchaser and the Stockholder have caused this
Agreement to be duly executed and delivered as of the date first written above.

 

BECKMAN COULTER, INC. A Delaware Corporation By   /s/    ARNOLD A.
PINKSTON           Name: Arnold A. Pinkston  

Title: Senior Vice President, General Counsel

and Secretary

LOUISIANA ACQUISITION SUB, INC. A Delaware Corporation By   /s/    ARNOLD A.
PINKSTON           Name: Arnold A. Pinkston   Title: Secretary KIM D.
BLICKENSTAFF /s/ KIM D. BLICKENSTAFF RITA BLICKENSTAFF /s/ RITA BLICKENSTAFF

SIGNATURE PAGE TO TENDER AND STOCKHOLDER SUPPORT AGREEMENT