Exhibit 99.2

                                VOTING AGREEMENT

      THIS VOTING AGREEMENT (this "AGREEMENT") is entered into as of March ___,
2004, by and between MOLECULAR DEVICES CORPORATION, a Delaware corporation
("PARENT"), and _______________ ("SHAREHOLDER").

                                    RECITALS

      A. Shareholder is a holder of CUFS over certain shares of common stock of
AXON INSTRUMENTS, INC., a California corporation (the "COMPANY") and the
"beneficial owner" (within the meaning of Rule 13d-3 under the Securities
Exchange Act of 1934, as amended), and is entitled to direct the depository
dominee (which holds the underlying shares on Shareholder's behalf) as to how it
should vote such shares at a meeting of the Company's shareholders.

      B. Parent, ASTROS ACQUISITION SUB I, INC., a California corporation and a
wholly owned subsidiary of Parent ("MERGER SUB I"), ASTROS ACQUISITION SUB II,
LLC, a California limited liability company and a wholly owned subsidiary of
Parent ("MERGER SUB II"), and the Company are entering into an Agreement and
Plan of Merger and Reorganization of even date herewith (the "MERGER AGREEMENT")
which provides (subject to the conditions set forth therein) for the merger of
Merger Sub I with and into the Company ("MERGER I") and immediately following
the effectiveness of Merger I, a merger of the Company with and into Merger Sub
II ("MERGER II," and together with Merger I, the "MERGERS") and each shareholder
of the Company will have the right to receive shares of Parent Common Stock (as
defined below) and cash in Merger I.

      C. In order to induce Parent to enter into the Merger Agreement,
Shareholder is entering into this Agreement.


                                    AGREEMENT

      The parties to this Agreement, intending to be legally bound, agree as
follows:

SECTION 1. CERTAIN DEFINITIONS

            For purposes of this Agreement:

            (A) The terms "ACQUISITION PROPOSAL" and "ACQUISITION TRANSACTION"
      shall have the respective meanings assigned to those terms in the Merger
      Agreement.

            (B) "COMPANY COMMON STOCK" shall mean the common stock, no par value
      per share, of the Company.

            (C) "EXPIRATION DATE" shall mean the earlier of the (i) date upon
      which the Merger Agreement is validly terminated pursuant to Section 8
      thereof, (ii) the date upon which Merger I is consummated, (iii) the
      mutual consent of Parent and Shareholder, or


                                       1

      (iv) the date of any modification, waiver or amendment to the Merger
      Agreement that reduces the Merger Consideration.

            (D) Shareholder shall be deemed to "OWN" or to have acquired
      "OWNERSHIP" of a security if Shareholder: (i) is the CUFS owner of such
      security; or (ii) is the "beneficial owner" (within the meaning of Rule
      13d-3 under the Securities Exchange Act of 1934) of such security.

            (E) "PARENT COMMON STOCK" shall mean the common stock, $.001 par
      value per share, of Parent.

            (F) "PERSON" shall mean any: (i) individual; (ii) corporation,
      limited liability company, partnership or other entity; or (iii)
      governmental authority.

            (G) "SUBJECT SECURITIES" shall mean: (i) all securities of the
      Company (including all shares of Company Common Stock and all options,
      warrants and other rights to acquire shares of Company Common Stock) Owned
      by Shareholder as of the date of this Agreement; and (ii) all securities
      of the Company (including all additional shares of Company Common Stock
      and all additional options, warrants and other rights to acquire shares of
      Company Common Stock) of which Shareholder acquires Ownership during the
      period from the date of this Agreement through the Expiration Date.

            (H) A Person shall be deemed to have a effected a "TRANSFER" of a
      security if such Person directly or indirectly: (i) sells, pledges,
      encumbers, grants an option with respect to, transfers or disposes of such
      security or any interest in such security to any Person other than Parent;
      (ii) enters into an agreement or commitment contemplating the possible
      sale of, pledge of, encumbrance of, grant of an option with respect to,
      transfer of or disposition of such security or any interest therein to any
      Person other than Parent; or (iii) reduces such Person's beneficial
      ownership of, interest in or risk relating to such security.

SECTION 2. TRANSFER OF SUBJECT SECURITIES AND VOTING RIGHTS

      2.1 RESTRICTION ON TRANSFER OF SUBJECT SECURITIES. Subject to Section 2.3,
during the period from the date of this Agreement through the Expiration Date,
Shareholder shall not, directly or indirectly, cause or permit any Transfer of
any of the Subject Securities to be effected.

      2.2 RESTRICTION ON TRANSFER OF VOTING RIGHTS. During the period from the
date of this Agreement through the Expiration Date, Shareholder shall ensure
that: (a) none of the Subject Securities is deposited into a voting trust; and
(b) no proxy is granted, and no voting agreement or similar agreement is entered
into, with respect to any of the Subject Securities.

      2.3 PERMITTED TRANSFERS. Section 2.1 shall not prohibit a Transfer of the
Subject Securities by Shareholder: (a) if Shareholder is an individual, to any
member of his or her immediate family or to a trust for the benefit of
Shareholder or any member of his or her immediate family; (b) if Shareholder is
an individual, upon the death of Shareholder; or (c) if Shareholder is a
partnership or limited liability company, to one or more partners or members of
Shareholder or to an affiliated corporation under common control with
Shareholder; provided,


                                       2

however, that a Transfer referred to in this sentence shall be permitted only
if, as a precondition to such Transfer, the transferee agrees in a writing,
reasonably satisfactory in form and substance to Parent, to be bound by the
terms of this Agreement.

SECTION 3. VOTING OF SHARES

      3.1 VOTING COVENANT. Shareholder hereby agrees that, prior to the
Expiration Date, at any meeting of the shareholders of the Company, however
called, and in any written action by consent of shareholders of the Company,
unless otherwise directed in writing by Parent, Shareholder shall cause the
Subject Securities to be voted:

            (A) in favor of the approval of the Merger Agreement and the
      principal terms thereof, in favor of each of the other actions
      contemplated by the Merger Agreement and in favor of any action in
      furtherance of any of the foregoing;

            (B) against any action or agreement that would result in a breach of
      any representation, warranty, covenant or obligation of the Company in the
      Merger Agreement; and

            (C) against the following actions (other than the Mergers and the
      transactions contemplated by the Merger Agreement): (A) any sale, license,
      disposition or acquisition of all or substantially all of the assets of
      the Company or any direct or indirect subsidiary or division of the
      Company; (B) any issuance, grant, disposition or acquisition of: (i) 20%
      or more of the capital stock or other equity security of the Company or
      any direct or indirect subsidiary of the Company; (ii) any option, call,
      warrant or right (whether or not immediately exercisable) to acquire 20%
      or more of the capital stock; or other equity security of the Company or
      any direct or indirect subsidiary of the Company or (iii) any security,
      instrument or obligation that is or may become convertible into or
      exchangeable for 20% or more of the capital stock or other equity security
      of the Company or any direct or indirect subsidiary of the Company; (C)
      any merger, consolidation, business combination, share exchange,
      reorganization or similar transaction involving the Company or any direct
      or indirect subsidiary of the Company in which the shareholders of the
      Company immediately prior to the transaction own less than 80% of any
      class of equity securities of the entity surviving or resulting form such
      transaction (or the ultimate parent entity thereof); (D) any liquidation
      or dissolution of the Company; (E) any change in a majority of the board
      of directors of the Company that is not approved in advance by at least a
      majority of the members of the board of directors of the Company as of the
      date of this Agreement (or their successors who were so approved); (F) any
      amendment to the Company's articles of incorporation or bylaws; (G) any
      material change in the capitalization of the Company or the Company's
      corporate structure; and (H) any other action which is intended, or could
      reasonably be expected, to impede, interfere with, delay, postpone,
      discourage or adversely affect the Mergers or any of the other
      transactions contemplated by the Merger Agreement or this Agreement.

Prior to the Expiration Date, Shareholder shall not enter into any agreement or
understanding with any Person to vote or give instructions in any manner
inconsistent with clause "(a)", "(b)", or "(c)" of the preceding sentence.

                                       3

      3.2 PROXY; FURTHER ASSURANCES.

            (A) Contemporaneously with the execution of this Agreement: (i)
      Shareholder shall deliver to Parent a proxy in the form attached to this
      Agreement as EXHIBIT A, which shall be irrevocable to the fullest extent
      permitted by law (at all times prior to the Expiration Date) with respect
      to the shares referred to therein (the "PROXY"); and (ii) Shareholder
      shall cause to be delivered to Parent an additional proxy (in the form
      attached hereto as EXHIBIT A) executed on behalf of the record owner of
      any outstanding shares of Company Common Stock that are owned beneficially
      (within the meaning of Rule 13d-3 under the Securities Exchange Act of
      1934), but not of record, by Shareholder.

            (B) Shareholder shall, at the expense of Parent, perform such
      further acts and execute such further proxies and other documents and
      instruments as may reasonably be required to vest in Parent the power to
      carry out and give effect to the provisions of this Agreement.

            (C) Shareholder shall not enter into any tender, voting or other
      such agreement, or grant a proxy or power of attorney, with respect to the
      Subject Securities that is inconsistent with this Agreement or otherwise
      take any other action with respect to the Subject Securities that would in
      any way restrict, limit or interfere with the performance of Shareholder's
      obligations hereunder or the transactions contemplated hereby.

SECTION 4. WAIVER OF DISSENTERS' RIGHTS

      To the extent permitted by applicable law, Shareholder hereby irrevocably
and unconditionally waives, and agrees to cause to be waived and to prevent the
exercise of, any dissenters' rights and any similar rights relating to Merger I
or any related transaction that Shareholder may have by virtue of, or with
respect to, any outstanding shares of Company Common Stock Owned by Shareholder.

SECTION 5. NO SOLICITATION

      Shareholder agrees that, during the period from the date of this Agreement
through the Expiration Date, Shareholder shall not, directly or indirectly, and
Shareholder shall ensure that his, her or its Representatives (as defined in the
Merger Agreement) do not, directly or indirectly: (a) solicit, initiate,
encourage, induce or facilitate the making, submission or announcement of any
Acquisition Proposal or take any action that could reasonably be expected to
lead to an Acquisition Proposal; (b) furnish any non-public information
regarding any of the Acquired Corporations (as defined in the Merger Agreement)
to any Person in connection with or in response to an Acquisition Proposal or an
inquiry or indication of interest that could reasonably be expected to lead to
an Acquisition Proposal; (c) engage in discussions or negotiations with any
Person with respect to any Acquisition Proposal; (d) approve, endorse or
recommend any Acquisition Proposal; or (e) enter into any letter of intent or
similar document or any Contract (as defined in the Merger Agreement)
contemplating or otherwise relating to any Acquisition Transaction; provided,
however, that in connection with any Acquisition Proposal that the Company's
board of directors (i) has determined to be a Superior Proposal or (ii) in good
faith


                                       4

determined could reasonably be expected to result in a Superior Proposal
pursuant to Section 4.4(b) of the Merger Agreement, Shareholder may provide
information and engage in discussions to the same extent as the Company is so
permitted pursuant to Section 4.4(b) of the Merger Agreement. Shareholder shall
immediately cease and discontinue, and Shareholder shall ensure that his, her or
its Representatives immediately cease and discontinue, any existing discussions
with any Person that relate to any Acquisition Proposal.

SECTION 6. REPRESENTATIONS AND WARRANTIES OF SHAREHOLDER

      Shareholder hereby represents and warrants to Parent as follows:

      6.1 AUTHORIZATION, ETC. Shareholder has all authority and capacity to
execute and deliver this Agreement and the Proxy and to perform his, her or its
obligations hereunder and thereunder. This Agreement and the Proxy have been
duly executed and delivered by Shareholder and constitute legal, valid and
binding obligations of Shareholder, enforceable against Shareholder in
accordance with their terms, subject to: (a) laws of general application
relating to bankruptcy, insolvency and the relief of debtors; and (b) rules of
law governing specific performance, injunctive relief and other equitable
remedies.

      6.2 NO CONFLICTS OR CONSENTS.

            (A) The execution and delivery of this Agreement and the Proxy by
      Shareholder do not, and the performance of this Agreement and the Proxy by
      Shareholder will not: (i) conflict with or violate any law, rule,
      regulation, order, decree or judgment applicable to Shareholder or any of
      the Subject Securities; or (ii) result in or constitute (with or without
      notice or lapse of time) any breach of or default under, or give to any
      other Person (with or without notice or lapse of time) any right of
      termination, amendment, acceleration or cancellation of, or result (with
      or without notice or lapse of time) in the creation of any encumbrance or
      restriction on any of the Subject Securities pursuant to, any contract to
      which Shareholder is a party or by which Shareholder or any of the Subject
      Securities is or may be bound or affected.

            (B) The execution and delivery of this Agreement and the Proxy by
      Shareholder do not, and the performance of this Agreement and the Proxy by
      Shareholder will not, require any consent or approval of any Person. The
      execution and delivery of any additional proxy pursuant to Section
      3.2(a)(ii) with respect to any shares of Company Common Stock that are
      owned beneficially but not of record by Shareholder do not, and the
      performance of any such additional proxy will not, require any consent or
      approval of any Person.

            (C) Except as disclosed on EXHIBIT B and except for indemnification
      as a director and officer, neither Shareholder nor any affiliate of
      Shareholder shall have any rights or claims under any Contract against the
      Company or the Parent after the Effective Time (as defined in the Merger
      Agreement) of Merger I.

      6.3 TITLE TO SECURITIES. As of the date of this Agreement: (a) Shareholder
holds CUFS (free and clear of any encumbrances or restrictions) over the number
of outstanding shares of Company Common Stock set forth under the heading
"Shares Held by CUFS" on the


                                       5

signature page hereof and is entitled to direct the depository nominee (which
holds the underlying shares on Shareholder's behalf) as to how it should vote
such shares at a meeting of the Company's shareholders; (b) Shareholder holds
(free and clear of any encumbrances or restrictions) the options, warrants and
other rights to acquire shares of Company Common Stock set forth under the
heading "Options and Other Rights" on the signature page hereof; (c) Shareholder
Owns the additional securities of the Company set forth under the heading
"Additional Securities Beneficially Owned" on the signature page hereof; and (d)
Shareholder does not directly or indirectly Own any shares of capital stock or
other securities of the Company, or any option, warrant or other right to
acquire (by purchase, conversion or otherwise) any shares of capital stock or
other securities of the Company, other than the shares and options, warrants and
other rights set forth on the signature page hereof.

      6.4 ACCURACY OF REPRESENTATIONS. The representations and warranties made
by Shareholder in this Agreement are accurate in all respects as of the date of
this Agreement, will be accurate in all respects at all times through the
Expiration Date and will be accurate in all respects as of the date of the
consummation of Merger I as if made on that date.

SECTION 7. REPRESENTATIONS AND WARRANTIES OF PARENT

      Parent hereby represents and warrants to Shareholder as follows:

      7.1 AUTHORIZATION, ETC. Parent is a company duly organized and validly
existing under the laws of the jurisdiction of its incorporation. Parent has all
necessary corporate power and authority to execute and deliver this Agreement
and to consummate the transactions contemplated hereby. The execution and
delivery of this Agreement and the consummation of the transactions contemplated
hereby by Parent have been duly authorized by all necessary action on the part
of Parent and constitutes legal, valid and binding obligations of Parent,
enforceable against Parent in accordance with their terms, subject to: (a) laws
of general application relating to bankruptcy, insolvency and the relief of
debtors; and (b) rules of law governing specific performance, injunctive relief
and other equitable remedies.

      7.2 NO CONFLICTS OR CONSENTS.

            (A) The execution and delivery of this Agreement by Parent do not,
      and the performance of this Agreement by Parent will not: (i) conflict
      with or violate any law, rule, regulation, order, decree or judgment
      applicable to Parent or by which he, she or it or any of his, her or its
      properties is bound; or (ii) result in or constitute (with or without
      notice or lapse of time) any breach of or default under, or give to any
      other Person (with or without notice or lapse of time) any right of
      termination, amendment, acceleration or cancellation of, or result (with
      or without notice or lapse of time) in the creation of any restriction on
      any of any contract to which Parent is a party or by which Parent or any
      of his, her or its affiliates or properties is bound.

            (B) The execution and delivery of this Agreement by Parent does not,
      and the performance of this Agreement by Parent will not, require any
      consent or approval of any Person, other than the board of directors of
      Parent.


                                       6

      7.4 ACCURACY OF REPRESENTATIONS. The representations and warranties made
by Parent in this Agreement are accurate in all respects as of the date of this
Agreement, will be accurate in all respects at all times through the Expiration
Date and will be accurate in all respects as of the date of the consummation of
Merger I as if made on that date.

SECTION 8. ADDITIONAL COVENANTS OF SHAREHOLDER

      8.1 SHAREHOLDER INFORMATION. Shareholder hereby agrees to permit Parent,
Merger Sub I and Merger Sub II to publish and disclose in the Form S-4
Registration Statement (as defined in the Merger Agreement) Shareholder's
identity and ownership of shares of Company Common Stock and the nature of
Shareholder's commitments, arrangements and understandings under this Agreement.

      8.2 FURTHER ASSURANCES. From time to time and without additional
consideration, Shareholder shall (at Parent's sole expense) execute and deliver,
or cause to be executed and delivered, such additional transfers, assignments,
endorsements, proxies, consents and other instruments as Parent may reasonably
require, and shall (at Parent's sole expense) take such further actions, as
Parent may reasonably request for the purpose of carrying out and furthering the
intent of this Agreement.

      8.3 LEGENDS. If requested by Parent, as soon as practicable after the
execution of this Agreement (and from time to time upon the acquisition by
Shareholder of Ownership of any shares of Company Common Stock prior to the
Expiration Date), Shareholder shall cause each certificate evidencing any
outstanding shares of Company Common Stock or other securities of the Company
Owned by Shareholder to be surrendered so that the transfer agent for such
securities may affix thereto a legend in the following form:

      THE SECURITY OR SECURITIES REPRESENTED BY THIS CERTIFICATE MAY NOT BE
      SOLD, EXCHANGED OR OTHERWISE TRANSFERRED OR DISPOSED OF EXCEPT IN
      COMPLIANCE WITH THE TERMS AND PROVISIONS OF A VOTING AGREEMENT DATED AS OF
      MARCH ___, 2004, AS IT MAY BE AMENDED, A COPY OF WHICH IS ON FILE AT THE
      PRINCIPAL EXECUTIVE OFFICES OF THE ISSUER.

SECTION 9. MISCELLANEOUS

      9.1 SURVIVAL OF REPRESENTATIONS, WARRANTIES AND AGREEMENTS. All
representations, warranties, covenants and agreements made by Shareholder and
Parent in this Agreement shall survive (i) any termination of the Merger
Agreement pursuant to Section 8 thereof; and (ii) the Expiration Date, unless
Merger I gets consummated.

      9.2 EXPENSES. All costs and expenses incurred in connection with the
transactions contemplated by this Agreement shall be paid by the party incurring
such costs and expenses.

      9.3 NOTICES. Any notice or other communication required or permitted to be
delivered to either party under this Agreement shall be in writing and shall be
deemed properly delivered, given and received when delivered (by hand, by
registered mail, by courier or express delivery service or by facsimile) to the
address or facsimile telephone number set forth beneath


                                       7

the name of such party below (or to such other address or facsimile telephone
number as such party shall have specified in a written notice given to the other
party):

      if to Shareholder:

            at the address set forth on the signature page hereof; and

      if to Parent:

            Molecular Devices Corporation
            1311 Orleans Drive
            Sunnyvale, CA 94089
            Attn:  Chief Financial Officer
            Fax:     (408) 747-3696

      9.4 SEVERABILITY. Any term or provision of this Agreement that is invalid
or unenforceable in any situation in any jurisdiction shall not affect the
validity or enforceability of the remaining terms and provisions hereof or the
validity or enforceability of the offending term or provision in any other
situation or in any other jurisdiction. If the final judgment of a court of
competent jurisdiction declares that any term or provision hereof is invalid or
unenforceable, the parties hereto agree that the court making such determination
shall have the power to limit the term or provision, to delete specific words or
phrases, or to replace any invalid or unenforceable term or provision with a
term or provision that is valid and enforceable and that comes closest to
expressing the intention of the invalid or unenforceable term or provision, and
this Agreement shall be enforceable as so modified. In the event such court does
not exercise the power granted to it in the prior sentence, the parties hereto
agree to negotiate in good faith to replace, and to replace, such invalid or
unenforceable term or provision with a valid and enforceable term or provision
that will achieve, to the extent possible, the economic, business and other
purposes of such invalid or unenforceable term.

      9.5 ENTIRE AGREEMENT. This Agreement, the Proxy and any other documents
delivered by the parties in connection herewith constitute the entire agreement
between the parties with respect to the subject matter hereof and thereof and
supersede all prior agreements and understandings between the parties with
respect thereto. No addition to or modification of any provision of this
Agreement shall be binding upon either party unless made in writing and signed
by both parties.

      9.6 ASSIGNMENT; BINDING EFFECT. Except as provided herein, neither this
Agreement nor any of the interests or obligations hereunder may be assigned or
delegated by any party hereto, and any attempted or purported assignment or
delegation of any of such interests or obligations shall be void. Subject to the
preceding sentence, this Agreement shall be binding upon Shareholder and his or
her heirs, estate, executors and personal representatives and his, her or its
successors and assigns, and shall inure to the benefit of Parent and its
successors and assigns. Without limiting any of the restrictions set forth in
Section 2 or Section 8.2 or elsewhere in this Agreement, this Agreement shall be
binding upon any Person to whom any Subject Securities are transferred. Nothing
in this Agreement is intended to confer on any Person (other than Parent and its
successors and assigns) any rights or remedies of any nature.


                                       8

      9.7 [INTENTIONALLY OMITTED.]

      9.8 SPECIFIC PERFORMANCE. The parties agree that irreparable damage would
occur in the event that any of the provisions of this Agreement or the Proxy
were not performed in accordance with its specific terms or were otherwise
breached. Shareholder agrees that, in the event of any breach or threatened
breach by Shareholder of any covenant or obligation contained in this Agreement
or in the Proxy, Parent shall be entitled (in addition to any other remedy that
may be available to it, including monetary damages) to seek and obtain: (a) a
decree or order of specific performance to enforce the observance and
performance of such covenant or obligation; and (b) an injunction restraining
such breach or threatened breach.

      9.9 NON-EXCLUSIVITY. The rights and remedies of Parent under this
Agreement are not exclusive of or limited by any other rights or remedies which
it may have, whether at law, in equity, by contract or otherwise, all of which
shall be cumulative (and not alternative). Without limiting the generality of
the foregoing, the rights and remedies of Parent under this Agreement, and the
obligations and liabilities of Shareholder under this Agreement, are in addition
to their respective rights, remedies, obligations and liabilities under common
law requirements and under all applicable statutes, rules and regulations.
Nothing in this Agreement shall limit any of Shareholder's obligations, or the
rights or remedies of Parent, under any Affiliate Agreement between Parent and
Shareholder; nothing in any such Affiliate Agreement shall limit any of
Shareholder's obligations, or any of the rights or remedies of Parent, under
this Agreement.

      9.10 GOVERNING LAW; VENUE.

            (A) This Agreement and the Proxy shall be construed in accordance
      with, and governed in all respects by, the laws of the State of California
      (without giving effect to principles of conflicts of laws).

            (B) Any legal action or other legal proceeding relating to this
      Agreement or the Proxy or the enforcement of any provision of this
      Agreement or the Proxy may be brought or otherwise commenced in any state
      or federal court located in the State of Delaware. Shareholder:

                  (i) expressly and irrevocably consents and submits to the
            jurisdiction of each state and federal court located in the State of
            Delaware in connection with any such legal proceeding;

                  (ii) agrees that service of any process, summons, notice or
            document by U.S. mail addressed to him or it at the address set
            forth on the signature page hereof shall constitute effective
            service of such process, summons, notice or document for purposes of
            any such legal proceeding;

                  (iii) agrees that each state and federal court located in the
            State of Delaware shall be deemed to be a convenient forum; and

                  (iv) agrees not to assert (by way of motion, as a defense or
            otherwise), in any such legal proceeding commenced in any state or
            federal court located in the State of Delaware, any claim that
            Shareholder is not subject personally to the


                                       9

            jurisdiction of such court, that such legal proceeding has been
            brought in an inconvenient forum, that the venue of such proceeding
            is improper or that this Agreement or the subject matter of this
            Agreement may not be enforced in or by such court.

      Nothing contained in this Section 9.10 shall be deemed to limit or
      otherwise affect the right of Parent to commence any legal proceeding or
      otherwise proceed against Shareholder in any other forum or jurisdiction.

            (C) SHAREHOLDER IRREVOCABLY WAIVES THE RIGHT TO A JURY TRIAL IN
      CONNECTION WITH ANY LEGAL PROCEEDING RELATING TO THIS AGREEMENT OR THE
      PROXY OR THE ENFORCEMENT OF ANY PROVISION OF THIS AGREEMENT OR THE PROXY.

      9.11 COUNTERPARTS. This Agreement may be executed in separate
counterparts, each of which when so executed and delivered shall be an original,
but all such counterparts shall together constitute one and the same instrument.

      9.12 CAPTIONS. The captions contained in this Agreement are for
convenience of reference only, shall not be deemed to be a part of this
Agreement and shall not be referred to in connection with the construction or
interpretation of this Agreement.

      9.13 ATTORNEYS' FEES. If any legal action or other legal proceeding
relating to this Agreement or the enforcement of any provision of this Agreement
is brought against Shareholder, the prevailing party shall be entitled to
recover reasonable attorneys' fees, costs and disbursements (in addition to any
other relief to which the prevailing party may be entitled).

      9.14 WAIVER. No failure on the part of Parent to exercise any power,
right, privilege or remedy under this Agreement, and no delay on the part of
Parent in exercising any power, right, privilege or remedy under this Agreement,
shall operate as a waiver of such power, right, privilege or remedy; no single
or partial exercise of any such power, right, privilege or remedy shall preclude
any other or further exercise thereof or of any other power, right, privilege or
remedy. Parent shall not be deemed to have waived any claim available to Parent
arising out of this Agreement, or any power, right, privilege or remedy of
Parent under this Agreement, unless the waiver of such claim, power, right,
privilege or remedy is expressly set forth in a written instrument duly executed
and delivered on behalf of Parent; any such waiver shall not be applicable or
have any effect except in the specific instance in which it is given.

      9.15 CONSTRUCTION.

            (A) For purposes of this Agreement, whenever the context requires:
      the singular number shall include the plural, and vice versa; the
      masculine gender shall include the feminine and neuter genders; the
      feminine gender shall include the masculine and neuter genders; and the
      neuter gender shall include masculine and feminine genders.

            (B) The parties agree that any rule of construction to the effect
      that ambiguities are to be resolved against the drafting party shall not
      be applied in the construction or interpretation of this Agreement.



                                       10

            (C) As used in this Agreement, the words "include" and "including,"
      and variations thereof, shall not be deemed to be terms of limitation, but
      rather shall be deemed to be followed by the words "without limitation."

            (D) Except as otherwise indicated, all references in this Agreement
      to "Sections" and "Exhibits" are intended to refer to Sections of this
      Agreement and Exhibits to this Agreement.

      9.16 INDEPENDENCE OF OBLIGATIONS. The covenants and obligations of
Shareholder set forth in this Agreement shall be construed as independent of any
other agreement or arrangement between Shareholder, on the one hand, and the
Company or Parent, on the other. The existence of any claim or cause of action
by Shareholder against the Company or Parent shall not constitute a defense to
the enforcement of any of such covenants or obligations against Shareholder.

      9.17 SHAREHOLDER CAPACITY. Shareholder is entering into this Agreement
solely in Shareholder's capacity as the CUFS and beneficial owner of the Subject
Securities. If Shareholder is or becomes during the term hereof a director or
officer of the Company, Shareholder makes no agreement or understanding in this
Agreement in Shareholder's capacity as such director or officer. Nothing in this
Agreement shall limit or affect any actions taken by Shareholder in
Shareholder's capacity as an officer or director of the Company. Nothing in this
Agreement shall be interpreted as obligating Shareholder to exercise any options
to acquire shares of Company Common Stock.



                                       11

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

                                   MOLECULAR DEVICES CORPORATION

                                   By:
                                      ------------------------------------------


                                   SHAREHOLDER

                                   ---------------------------------------------
                                   Name:

                                   Address:   ----------------------------------
                                              ----------------------------------

                                   Facsimile: ---------------------



                                 SHARES HELD BY CUFS    OPTIONS AND OTHER RIGHTS      ADDITIONAL SECURITIES
                                                                                           BENEFICIALLY
                                                                                               OWNED

                                                                             
Company Common Stock




                                       12

                                    EXHIBIT A

                            FORM OF IRREVOCABLE PROXY

      The undersigned shareholder ("SHAREHOLDER") of AXON INSTRUMENTS, INC., a
California corporation (the "COMPANY"), hereby irrevocably (to the fullest
extent permitted by law) appoints and constitutes JOSEPH D. KEEGAN, PH.D.,
TIMOTHY A. HARKNESS and MOLECULAR DEVICES CORPORATION, a Delaware corporation
("PARENT"), and each of them, the attorneys and proxies of Shareholder with full
power of substitution and resubstitution, to the full extent of Shareholder's
rights with respect to: (i) the outstanding shares of capital stock of the
Company owned by CUFS by Shareholder as of the date of this proxy, which shares
are specified on the final page of this proxy; and (ii) any and all other shares
of capital stock of the Company which Shareholder may acquire on or after the
date hereof. (The shares of the capital stock of the Company referred to in
clauses "(i)" and "(ii)" of the immediately preceding sentence are collectively
referred to as the "SHARES.") Upon the execution hereof, all prior proxies given
by Shareholder with respect to any of the Shares are hereby revoked, and
Shareholder agrees that no subsequent proxies will be given with respect to any
of the Shares but only for the matters set forth below.

      This proxy is irrevocable, is coupled with an interest and is granted in
connection with the Voting Agreement, dated as of the date hereof, between
Parent and Shareholder (the "VOTING AGREEMENT"), and is granted in consideration
of Parent entering into the Agreement and Plan of Merger and Reorganization,
dated as of the date hereof, among Parent, Astros Acquisition Sub I, Inc.,
Astros Acquisition Sub II, LLC and the Company (the "MERGER AGREEMENT") which
provides (subject to the conditions set forth therein) for the merger of Merger
Sub I with and into the Company ("MERGER I") and immediately following the
effectiveness of Merger I, a merger of the Company with and into Merger Sub II
("MERGER II," and together with Merger I, the "MERGERS"). This proxy will
terminate on the Expiration Date (as defined in the Voting Agreement).

      The attorneys and proxies named above will be empowered, and may exercise
this proxy, to vote the Shares at any time until the Expiration Date (as defined
in the Voting Agreement) at any meeting of the shareholders of the Company,
however called, and in connection with any written action by consent of
shareholders of the Company:

            (i) in favor the approval of the Merger Agreement and the principal
      terms thereof, in favor of each of the other actions contemplated by the
      Merger Agreement and in favor of any action in furtherance of any of the
      foregoing;

            (ii) against any action or agreement that would result in a breach
      of any representation, warranty, covenant or obligation of the Company in
      the Merger Agreement; and

            (ii) against the following actions (other than the Mergers and the
      transactions contemplated by the Merger Agreement): (A) any sale, license,
      disposition or acquisition of all or substantially all of the assets of
      the Company or any direct or indirect subsidiary or division of the
      Company; (B) any issuance, grant, disposition or acquisition of: (i) 20%
      or more of the capital stock or other equity security of the Company or
      any direct or

      indirect subsidiary of the Company; (ii) any option, call, warrant or
      right (whether or not immediately exercisable) to acquire 20% or more of
      the capital stock; or other equity security of the Company or any direct
      or indirect subsidiary of the Company or (iii) any security, instrument or
      obligation that is or may become convertible into or exchangeable for 20%
      or more of the capital stock or other equity security of the Company or
      any direct or indirect subsidiary of the Company; (C) any merger,
      consolidation, business combination, share exchange, reorganization or
      similar transaction involving the Company or any direct or indirect
      subsidiary of the Company in which the shareholders of the Company
      immediately prior to the transaction own less than 80% of any class of
      equity securities of the entity surviving or resulting form such
      transaction (or the ultimate parent entity thereof); (D) any liquidation
      or dissolution of the Company; (E) any change in a majority of the board
      of directors of the Company that is not approved in advance by at least a
      majority of the members of the board of directors of the Company as of the
      date of the Voting Agreement (or their successors who were so approved);
      (F) any amendment to the Company's articles of incorporation or bylaws;
      (G) any material change in the capitalization of the Company or the
      Company's corporate structure; and (H) any other action which is intended,
      or could reasonably be expected, to impede, interfere with, delay,
      postpone, discourage or adversely affect the Mergers or any of the other
      transactions contemplated by the Merger Agreement or the Voting Agreement.

      Shareholder may vote the Shares on all other matters not referred to in
this proxy, and the attorneys and proxies named above may not exercise this
proxy with respect to such other matters.

      This proxy shall be binding upon the heirs, estate, executors, personal
representatives, successors and assigns of Shareholder (including any transferee
of any of the Shares).

      Any term or provision of this proxy that is invalid or unenforceable in
any situation in any jurisdiction shall not affect the validity or
enforceability of the remaining terms and provisions hereof or the validity or
enforceability of the offending term or provision in any other situation or in
any other jurisdiction. If the final judgment of a court of competent
jurisdiction declares that any term or provision hereof is invalid or
unenforceable, Shareholder agrees that the court making such determination shall
have the power to limit the term or provision, to delete specific words or
phrases, or to replace any invalid or unenforceable term or provision with a
term or provision that is valid and enforceable and that comes closest to
expressing the intention of the invalid or unenforceable term or provision, and
this proxy shall be enforceable as so modified. In the event such court does not
exercise the power granted to it in the prior sentence, Shareholder agrees to
replace such invalid or unenforceable term or provision with a valid and
enforceable term or provision that will achieve, to the extent possible, the
economic, business and other purposes of such invalid or unenforceable term.

Dated:  March ___, 2004




                                 SHARES HELD BY CUFS    OPTIONS AND OTHER RIGHTS      ADDITIONAL SECURITIES
                                                                                           BENEFICIALLY
                                                                                               OWNED
                                                                             
Company Common Stock





                                    EXHIBIT B
                                    CONTRACTS