EXHIBIT 10.24

                          MOLECULAR DEVICES CORPORATION
                 1995 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

             ADOPTED BY THE BOARD OF DIRECTORS ON SEPTEMBER 13, 1995
                APPROVED BY THE STOCKHOLDERS ON DECEMBER 12, 1995
              AMENDED BY THE BOARD OF DIRECTORS ON JANUARY 29, 1999
                  APPROVED BY THE STOCKHOLDERS ON MAY 20, 1999
               AMENDED BY THE BOARD OF DIRECTORS ON JULY 29, 2004

1. PURPOSE.

      (a) The purpose of the 1995 Non-Employee Directors' Stock Option Plan (the
"Plan") is to provide a means by which each director of MOLECULAR DEVICES
CORPORATION (the "Company") who is not otherwise an employee of the Company or
of any Affiliate of the Company (each such person being hereafter referred to as
a "Non-Employee Director") will be given an opportunity to purchase stock of the
Company.

      (b) The word "Affiliate" as used in the Plan means any parent corporation
or subsidiary corporation of the Company as those terms are defined in Sections
424(e) and (f), respectively, of the Internal Revenue Code of 1986, as amended
from time to time (the "Code").

      (c) The Company, by means of the Plan, seeks to retain the services of
persons now serving as Non-Employee Directors of the Company, to secure and
retain the services of persons capable of serving in such capacity, and to
provide incentives for such persons to exert maximum efforts for the success of
the Company.

2. ADMINISTRATION.

      (a) The Plan shall be administered by the Board of Directors of the
Company (the "Board") unless and until the Board delegates administration to a
committee, as provided in subparagraph 2(b).

      (b) The Board may delegate administration of the Plan to a committee
composed of not fewer than two (2) members of the Board (the "Committee"). If
administration is delegated to a Committee, the Committee shall have, in
connection with the administration of the Plan, the powers theretofore possessed
by the Board, subject, however, to such resolutions, not inconsistent with the
provisions of the Plan, as may be adopted from time to time by the Board. If the
Committee is delegated authority to amend or fix the timing or terms of options
granted under the Plan, then the composition of the Committee shall comply with
the requirements for exemption of option grants from the application of Section
16 of the Securities Exchange Act of 1934, or the terms of such options shall be
such as to qualify such options for such exemption. The Board may abolish the
Committee at any time and revest in the Board the administration of the Plan.

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3. SHARES SUBJECT TO THE PLAN.

      (a) Subject to the provisions of paragraph 10 relating to adjustments upon
changes in stock, the stock that may be sold pursuant to options granted under
the Plan shall not exceed in the aggregate three hundred forty-seven thousand
five hundred (347,500) shares of the Company's common stock. If any option
granted under the Plan shall for any reason expire or otherwise terminate
without having been exercised in full, the stock not purchased under such option
shall again become available for the Plan.

      (b) The stock subject to the Plan may be unissued shares or reacquired
shares, bought on the market or otherwise.

4. ELIGIBILITY.

      (a) Options shall be granted only to Non-Employee Directors of the
Company.

5. NON-DISCRETIONARY GRANTS.

      (a) Upon the date of the initial approval of the Plan by the Board (the
"Adoption Date"), each person who is then a Non-Employee Director automatically
shall be granted an option to purchase sixteen thousand five hundred (16,500)
shares of common stock of the Company on the terms and conditions set forth
herein.

      (b) Each person who is, after the Adoption Date, elected for the first
time to be a Non-Employee Director automatically shall, upon the date of his
initial election to be a Non-Employee Director by the Board or shareholders of
the Company, be granted an option to purchase ten thousand (10,000) shares of
common stock of the Company on the terms and conditions set forth herein.

      (c) Following the Adoption Date, each Non-Employee Director shall
automatically be granted an additional Option to purchase four thousand (4,000)
shares of common stock of the Company on the terms and conditions set forth
herein immediately following each annual meeting of stockholders.

      (d) Notwithstanding anything to the contrary set forth in this Section 5,
each Non-Employee Director who received a stock option grant pursuant to this
Plan in September 1998 (a "September 1998 Grant") shall not be entitled to
future grants under this Plan until the September 1998 Grant shall have fully
vested. On the date that the September 1998 Grant shall have fully vested, such
Non-Employee Director shall be treated as having been initially elected to be a
Non-Employee Director on such date and receive the stock option referenced in
Section 5(b) and, thereafter, shall be eligible to receive the stock options
referenced in Section 5(c).

6. OPTION PROVISIONS.

      Each option shall be subject to the following terms and conditions:

      (a) The term of each option commences on the date it is granted and,
unless sooner terminated as set forth herein, expires on the date ("Expiration
Date") ten (10) years from the

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date of grant. If the optionee's service as a Non-Employee Director or employee
of or consultant to the Company or any Affiliate terminates for any reason or
for no reason, the option shall terminate on the earlier of the Expiration Date
or the date three (3) months following the date of termination of all such
service; provided, however, that if such termination of service is due to the
optionee's death, the option shall terminate on the earlier of the Expiration
Date or eighteen (18) months following the date of the optionee's death. In any
and all circumstances, an option may be exercised following termination of the
optionee's service as a Non-Employee Director or employee of or consultant to
the Company or any Affiliate only as to that number of shares as to which it was
exercisable on the date of termination of such all service under the provisions
of subparagraph 6(e).

      (b) Subject to subparagraph 4(b), the exercise price of each option shall
be one hundred percent (100%) of the fair market value of the stock subject to
such option on the date such option is granted.

      (c) Payment of the exercise price of each option is due in full in cash
upon any exercise when the number of shares being purchased upon such exercise
is less than 1,000 shares; but when the number of shares being purchased upon an
exercise is 1,000 or more shares, the optionee may elect to make payment of the
exercise price under one of the following alternatives:

            (i) Payment of the exercise price per share in cash at the time of

exercise; or

            (ii) Provided that at the time of the exercise the Company's common
stock is publicly traded and quoted regularly in the Wall Street Journal,
payment by delivery of shares of common stock of the Company already owned by
the optionee, held for the period required to avoid a charge to the Company's
reported earnings, and owned free and clear of any liens, claims, encumbrances
or security interest, which common stock shall be valued at its fair market
value on the date preceding the date of exercise; or

            (iii) Payment by a combination of the methods of payment specified
in subparagraph 6(c)(i) and 6(c)(ii) above.

      Notwithstanding the foregoing, this option may be exercised pursuant to a
program developed under Regulation T as promulgated by the Federal Reserve Board
which results in the receipt of cash (or check) by the Company prior to the
issuance of shares of the Company's common stock.

      (d) An option shall not be transferable except by will or by the laws of
descent and distribution, or pursuant to a domestic relations order satisfying
the requirements of Rule 16a-12 under the Securities Exchange Act of 1934 (a
"DRO") and shall be exercisable during the lifetime of the person to whom the
option is granted only by such person (or by his guardian or legal
representative) or transferee pursuant to a DRO. Notwithstanding the foregoing,
the optionee may, by delivering written notice to the Company in a form
satisfactory to the

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Company, designate a third party who, in the event of the death of the optionee,
shall thereafter be entitled to exercise the option.

      (e) The option shall become exercisable in installments over a period of
four years from the date of grant in equal annual installments commencing on the
date one year after the date of grant of the option, provided that the optionee
has, during the entire period prior to such vesting date, continuously served as
a Non-Employee Director or employee of or consultant to the Company or any
Affiliate of the Company, whereupon such option shall become fully exercisable
in accordance with its terms with respect to that portion of the shares
represented by that installment. For purposes of vesting under this subparagraph
6(e), attendance at no less than two-thirds (2/3) of the Board meetings
occurring during an installment period is required in order for an optionee
serving as a Non-Employee Director to vest for such installment; failure to
satisfy this requirement during any particular installment period shall result
in an abatement of the vesting of the option during the applicable installment
period and the aggregate vesting period of such option shall be increased by one
additional year.

      (f) The Company may require any optionee, or any person to whom an option
is transferred under subparagraph 6(d), as a condition of exercising any such
option: (i) to give written assurances satisfactory to the Company as to the
optionee's knowledge and experience in financial and business matters; and (ii)
to give written assurances satisfactory to the Company stating that such person
is acquiring the stock subject to the option for such person's own account and
not with any present intention of selling or otherwise distributing the stock.
These requirements, and any assurances given pursuant to such requirements,
shall be inoperative if (i) the issuance of the shares upon the exercise of the
option has been registered under a then-currently-effective registration
statement under the Securities Act of 1933, as amended (the "Securities Act"),
or (ii), as to any particular requirement, a determination is made by counsel
for the Company that such requirement need not be met in the circumstances under
the then-applicable securities laws.

      (g) Notwithstanding anything to the contrary contained herein, an option
may not be exercised unless the shares issuable upon exercise of such option are
then registered under the Securities Act or, if such shares are not then so
registered, the Company has determined that such exercise and issuance would be
exempt from the registration requirements of the Securities Act.

7. COVENANTS OF THE COMPANY.

      (a) During the terms of the options granted under the Plan, the Company
shall keep available at all times the number of shares of stock required to
satisfy such options.

      (b) The Company shall seek to obtain from each regulatory commission or
agency having jurisdiction over the Plan such authority as may be required to
issue and sell shares of stock upon exercise of the options granted under the
Plan; provided, however, that this undertaking shall not require the Company to
register under the Securities Act either the Plan, any option granted under the
Plan, or any stock issued or issuable pursuant to any such option. If, after
reasonable efforts, the Company is unable to obtain from any such regulatory
commission or agency the authority which counsel for the Company deems necessary
for the

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lawful issuance and sale of stock under the Plan, the Company shall be relieved
from any liability for failure to issue and sell stock upon exercise of such
options.

8. USE OF PROCEEDS FROM STOCK.

      Proceeds from the sale of stock pursuant to options granted under the Plan
shall constitute general funds of the Company.

9. MISCELLANEOUS.

      (a) Neither an optionee nor any person to whom an option is transferred
under subparagraph 6(d) shall be deemed to be the holder of, or to have any of
the rights of a holder with respect to, any shares subject to such option unless
and until such person has satisfied all requirements for exercise of the option
pursuant to its terms.

      (b) Nothing in the Plan or in any instrument executed pursuant thereto
shall confer upon any Non-Employee Director any right to continue in the service
of the Company or any Affiliate or shall affect any right of the Company, its
Board or stockholders or any Affiliate to terminate the service of any
Non-Employee Director with or without cause.

      (c) No Non-Employee Director, individually or as a member of a group, and
no beneficiary or other person claiming under or through him, shall have any
right, title or interest in or to any option reserved for the purposes of the
Plan except as to such shares of common stock, if any, as shall have been
reserved for him pursuant to an option granted to him.

      (d) In connection with each option made pursuant to the Plan, it shall be
a condition precedent to the Company's obligation to issue or transfer shares to
a Non-Employee Director, or to evidence the removal of any restrictions on
transfer, that such Non-Employee Director make arrangements satisfactory to the
Company to insure that the amount of any federal or other withholding tax
required to be withheld with respect to such sale or transfer, or such removal
or lapse, is made available to the Company for timely payment of such tax.

            (i) If the common stock is listed on any established stock exchange
or a national market system, including without limitation the National Market
System of the National Association of Securities Dealers, Inc. Automated
Quotation ("Nasdaq") System, the Fair Market Value of a share of common stock
shall be the closing sales price for such stock (or the closing bid, if no sales
were reported) as quoted on such system or exchange (or the exchange with the
greatest volume of trading in common stock) on the last market trading day prior
to the day of determination, as reporting in the Wall Street Journal or such
other source as the Board deems reliable;

            (ii) If the common stock is quoted on the Nasdaq System (but not on
the National Market System thereof) or is regularly quoted by a recognized
securities dealer but selling prices are not reported, the Fair Market Value of
a share of common stock shall be the mean between the bid and asked prices for
the common stock on the last market trading day prior to the day of
determination, as reported in the Wall Street Journal or such other source as
the Board deems reliable;

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            (iii) In the absence of an established market for the common stock,
the Fair Market Value shall be determined in good faith by the Board.

10. ADJUSTMENTS UPON CHANGES IN STOCK.

      (a) If any change is made in the stock subject to the Plan, or subject to
any option granted under the Plan (through merger, consolidation,
reorganization, recapitalization, stock dividend, dividend in property other
than cash, stock split, liquidating dividend, combination of shares, exchange of
shares, change in corporate structure or otherwise), the Plan and outstanding
options will be appropriately adjusted in the class(es) and maximum number of
shares subject to the Plan and the class(es) and number of shares and price per
share of stock subject to outstanding options.

      (b) In the event of: (1) a merger or consolidation in which the Company is
not the surviving corporation; (2) a reverse merger in which the Company is the
surviving corporation but the shares of the Company's common stock outstanding
immediately preceding the merger are converted by virtue of the merger into
other property, whether in the form of securities, cash or otherwise; or (3) any
other capital reorganization in which more than fifty percent (50%) of the
shares of the Company entitled to vote are exchanged, the time during which
options outstanding under the Plan may be exercised shall be accelerated and the
options terminated if not exercised prior to such event.

11. AMENDMENT OF THE PLAN.

      (a) The Board at any time, and from time to time, may amend the Plan,
provided, however, that except as provided in paragraph 10 relating to
adjustments upon changes in stock, no amendment shall be effective unless
approved by the stockholders of the Company within twelve (12) months before or
after the adoption of the amendment, where the amendment will:

            (i) Increase the number of shares which may be issued under the
Plan;

            (ii) Modify the requirements as to eligibility for participation in
the Plan (to the extent such modification requires stockholder approval in order
for the Plan to comply with the requirements of Rule 16b-3); or

            (iii) Modify the Plan in any other way if such modification requires
stockholder approval in order for the Plan to comply with the requirements of
Nasdaq or any securities exchange on which the Company desires prices for its
common stock to be quoted.

      (b) Rights and obligations under any option granted before any amendment
of the Plan shall not be impaired by such amendment unless (i) the Company
requests the consent of the person to whom the option was granted and (ii) such
person consents in writing.

12. TERMINATION OR SUSPENSION OF THE PLAN.

      (a) The Board may suspend or terminate the Plan at any time. No options
may be granted under the Plan while the Plan is suspended or after it is
terminated.

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      (b) Rights and obligations under any option granted while the Plan is in
effect shall not be impaired by suspension or termination of the Plan, except
with the consent of the person to whom the option was granted.

      (c) The Plan shall terminate upon the occurrence of any of the events
described in subparagraph 10(b) above.

13. PRIOR STOCKHOLDER APPROVAL OF OPTION REPRICINGS. Notwithstanding anything to
the contrary herein, the Board shall not, without first obtaining the approval
of the stockholders of the Company, (i) reduce the exercise price of any
outstanding option under the Plan, (ii) cancel any outstanding option under the
Plan and replace it with an option with a lower exercise price, (iii) accept any
outstanding option in exchange for a new option with a lower exercise price, or
(iv) take any other action that is treated as a "repricing" under generally
accepted accounting principles.

14. EFFECTIVE DATE OF PLAN; CONDITIONS OF EXERCISE.

      (a) The Plan shall become effective upon adoption by the Board of
Directors, subject to the condition subsequent that the Plan is approved by the
stockholders of the Company.

      (b) No option granted under the Plan shall be exercised or exercisable
unless and until the condition of subparagraph 14(a) above has been met.

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