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                                                                   EXHIBIT 10.38

                          MOLECULAR DEVICES CORPORATION
                             2001 STOCK OPTION PLAN

               ADOPTED BY THE BOARD OF DIRECTORS ON JULY 26, 2001
                    AMENDED BY THE BOARD ON FEBRUARY 6, 2003
                        STOCKHOLDER APPROVAL NOT REQUIRED

1.    PURPOSES.

      (a) The purpose of the Plan is to provide a means by which selected
      Employees of the Company or its Affiliates who are working or residing
      outside of the United States and are not Officers or Directors may be
      given an opportunity to purchase stock of the Company.

      (b) The Company, by means of the Plan, seeks to retain the services of
      persons who are eligible to receive Options, to secure and retain the
      services of new members of this group and to provide incentives for such
      persons to exert maximum efforts for the success of the Company and its
      Affiliates.

2.    DEFINITIONS.

      (a) "Affiliate" means any "parent" or "subsidiary", whether now or
      hereafter existing, as those terms are defined in Rule 405 promulgated
      under the Securities Act of 1933, as amended of the United States of
      America.

      (b) "Board" means the Board of Directors of the Company.

      (c) "Code" means the Internal Revenue Code of 1986, as amended.

      (d) "Committee" means a Committee appointed by the Board in accordance
      with subsection 3(c) of the Plan.

      (e) "Company" means Molecular Devices Corporation.

      (f) "Consultant" means any person, including an advisor, engaged by the
      Company or an Affiliate to render consulting services and who is
      compensated for such services, provided that the term "Consultant" shall
      not include Directors who are paid only a director's fee by the Company or
      who are not compensated by the Company for their services as Directors.

      (g) "Continuous Status as an Employee, Director or Consultant" means the
      employment or relationship as a Director or Consultant with the Company or
      an Affiliate of the Company is not interrupted or terminated. The Board,
      in its sole discretion, may determine whether Continuous Status as an
      Employee, Director or Consultant shall be considered interrupted in the
      case of any leave of absence approved by the Board, including sick leave,
      military leave, or any other personal leave.

      (i) "Director" means a member of the Board.

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      (j) "Employee" means any person, including an Officer, classified for tax
      purposes as an "employee" by the Company or any Affiliate of the Company.
      Neither service as a Director nor payment of a director's fee by the
      Company shall be sufficient to constitute status as an "employee."

      (k) "Exchange Act" means the Securities Exchange Act of 1934, as amended.

      (l) "Fair Market Value" means as of any date, the value of the Common
      Stock of the Company determined as follows:

            (1) 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 reported in the Wall Street
            Journal or such other source as the Board deems reliable;

            (2) 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;

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

      (n) "Non-Employee Director" means a Director of the Company who either (i)
      is not a current Employee or Officer of the Company or its parent or a
      subsidiary, does not receive compensation (directly or indirectly) from
      the Company or its parent or a subsidiary for services rendered as a
      consultant or in any capacity other than as a Director (except for an
      amount as to which disclosure would not be required under Item 404(a) of
      Regulation S-K promulgated pursuant to the Securities Act ("Regulation
      S-K")), does not possess an interest in any other transaction as to which
      disclosure would be required under Item 404(a) of Regulation S-K and is
      not engaged in a business relationship as to which disclosure would be
      required under Item 404(b) of Regulation S-K; or (ii) is otherwise
      considered a "non-employee director" for purposes of Rule 16b-3.

      (o) "Nonstatutory Stock Option" means an Option not intended to qualify as
      an "incentive stock option" under Section 422 of the Code.

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      (p) "Officer" means a person who is an officer of the Company within the
      meaning of that term in Rule 4350(i)(1)(A) of the Rules of the National
      Association of Securities Dealers, Inc. (or any successor to that rule).

      (q) "Option" means a Nonstatutory Stock Option granted pursuant to the
      Plan.

      (r) "Option Agreement" means a written agreement between the Company and
      an Optionee evidencing the terms and conditions of an individual Option
      grant. Each Option Agreement shall be subject to the terms and conditions
      of the Plan.

      (s) "Optionee" means an Employee, Director or Consultant who holds an
      outstanding Option.

      (u) "Plan" means this Molecular Devices Corporation 2001 Stock Option
      Plan.

      (v) "Rule 16b-3" means Rule 16b-3 of the Exchange Act or any successor to
      Rule 16b-3, as in effect when discretion is being exercised with respect
      to the Plan.

3.    ADMINISTRATION.

      (a) The Plan shall be administered by the Board unless and until the Board
      delegates administration to a Committee, as provided in subsection 3(c).

      (b) The Board shall have the power, subject to, and within the limitations
      of, the express provisions of the Plan:

            (1) To determine from time to time which of the persons eligible
            under the Plan shall be granted Options; when and how each Option
            shall be granted; the provisions of each Option granted (which need
            not be identical), including the time or times such Option may be
            exercised in whole or in part; and the number of shares for which an
            Option shall be granted to each such person.

            (2) To construe and interpret the Plan and Options granted under it,
            and to establish, amend and revoke rules and regulations for its
            administration. The Board, in the exercise of this power, may
            correct any defect, omission or inconsistency in the Plan or in any
            Option Agreement, in a manner and to the extent it shall deem
            necessary or expedient to make the Plan fully effective.

            (3) To amend the Plan or an Option as provided in Section 11.

            (4) To effect, at any time and from time to time, with the consent
            of any adversely affected Optionee, (1) the cancellation of any
            outstanding Option under the Plan and the grant in substitution
            therefor, more than 6 months after the date of cancellation, of a
            new Option under the Plan covering the same or a different number of
            shares or (2) any other similar action that is not treated as a
            "repricing" under generally accepted accounting principles.

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            (5) Generally, to exercise such powers and to perform such acts as
            the Board deems necessary or expedient to promote the best interests
            of the Company.

      (c) The Board may delegate administration of the Plan to a committee
      composed of not fewer than two (2) members (the "Committee"), all of the
      members of which Committee may be Non-Employee Directors if exemption of
      an Option or Options from the restrictions of Section 16(b) of the
      Exchange Act is deemed necessary or desirable. 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
      (and references in this Plan to the Board shall thereafter be to the
      Committee), subject, however, to such resolutions, not inconsistent with
      the provisions of the Plan, as may be adopted from time to time by the
      Board. The Board may abolish the Committee at any time and revest in the
      Board the administration of the Plan. Notwithstanding anything in this
      Section 3 to the contrary, the Board or the Committee may delegate to a
      committee of one or more members of the Board the authority to grant
      Options to eligible persons who are not then subject to Section 16 of the
      Exchange Act.

      (d) All determinations, interpretations and constructions made by the
      Board in good faith shall not be subject to review by any person and shall
      be final, binding and conclusive on all persons.

4.    SHARES SUBJECT TO THE PLAN.

      (a) Subject to the provisions of Section 10 relating to adjustments upon
      changes in stock, the stock that may be sold pursuant to Options shall not
      exceed in the aggregate one hundred thousand (100,000) shares of Company
      common stock. If any Option granted under the Plan shall for any reason
      expire or otherwise terminate, in whole or in part, without having been
      exercised in full, the stock not acquired shall revert to and again become
      available for issuance under this Plan.

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

5.    ELIGIBILITY.

Options may be granted only to Employees who, at the time of grant, are working
or residing outside of the United States and are not Officers or Directors.

6.    OPTION PROVISIONS.

Each Option shall be in such form and shall contain such terms and conditions as
the Board shall deem appropriate. The provisions of separate Options need not be
identical, but each Option shall include (through incorporation of provisions
hereof by reference in the Option or otherwise) the substance of each of the
following provisions:

      (a) Term. No Option shall be exercisable after the expiration of twelve
      (12) years from the date it was granted.

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      (b) Price. Unless otherwise provided expressly by the Board or Committee,
      the per share exercise price of each Option shall not be less than
      eighty-five percent (85%) of the Fair Market Value of a share of the
      Company's Common Stock on the date of grant.

      (c) Consideration. The purchase price of stock acquired pursuant to
      exercise of an Option shall be paid, to the extent permitted by applicable
      statutes and regulations, either (i) in cash at the time the Option is
      exercised, or (ii) at the discretion of the Board or the Committee, at the
      time of the grant of the Option, (A) by delivery to the Company of other
      common stock of the Company, (B) according to a deferred payment or other
      arrangement (which may include, without limiting the generality of the
      foregoing, the use of other common stock of the Company) with the person
      to whom the Option is granted or to whom the Option is transferred
      pursuant to subsection 6(d), or (C) in any other form of legal
      consideration that may be acceptable to the Board.

      In the case of any deferred payment arrangement, interest shall be
      compounded at least annually and shall be charged at the minimum rate of
      interest necessary to avoid (1) the treatment as interest, under any
      applicable provisions of the Code, of any amounts other than amounts
      stated to be interest under the deferred payment arrangement and (2) the
      treatment of the Option as a variable award for financial accounting
      purposes.

      (d) Transferability. In the absence of a provision on transferability in
      an Option Agreement, a Nonstatutory Stock 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 16b-3 and the
      rules thereunder (a "DRO"), and shall be exercisable during the lifetime
      of the person to whom the Option is granted only by such person or any
      transferee pursuant to a DRO. The person to whom a Nonstatutory Stock
      Option is granted may, by delivering written notice to the Company, in a
      form satisfactory to the Company, designate a third party who, in the
      event of the death of the Optionee, shall thereafter be entitled to
      exercise the Nonstatutory Stock Option.

      (e) Vesting. The total number of shares of stock subject to an Option may,
      but need not, be allotted in periodic installments (which may, but need
      not, be equal). The Option Agreement may provide that from time to time
      during each of such installment periods, the Option may become exercisable
      ("vest") with respect to some or all of the shares allotted to that
      period, and may be exercised with respect to some or all of the shares
      allotted to such period and/or any prior period as to which the Option
      became vested but was not fully exercised. The Option may be subject to
      such other terms and conditions on the time or times when it may be
      exercised (which may be based on performance or other criteria) as the
      Board may deem appropriate. The provisions of this subsection 6(e) are
      subject to any Option provisions governing the minimum number of shares as
      to which an Option may be exercised.

      (f) Investment Assurances. The Company may require any Optionee, or any
      person to whom an Option is transferred under subsection 6(d), as a
      condition of exercising any such Option, (1) to give written assurances
      satisfactory to the Company as to the Optionee's knowledge and experience
      in financial and business matters and/or to employ a purchaser
      representative reasonably satisfactory to the Company

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      who is knowledgeable and experienced in financial and business matters,
      and that he or she is capable of evaluating, alone or together with the
      purchaser representative, the merits and risks of exercising the Option;
      and (2) 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. The foregoing 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. The Company may, upon advice of
      counsel to the Company, place legends on stock certificates issued under
      the Plan as such counsel deems necessary or appropriate in order to comply
      with applicable securities laws, including, but not limited to, legends
      restricting the transfer of the stock.

      (g) Termination of Employment or Relationship as a Director or Consultant.
      In the event an Optionee's Continuous Status as an Employee, Director or
      Consultant terminates (other than upon the Optionee's death or
      disability), the Optionee may exercise his or her Option (to the extent
      that the Optionee was entitled to exercise it at the date of termination)
      but only within such period of time ending on the earlier of (i) the date
      three (3) months after the termination of the Optionee's Continuous Status
      as an Employee, Director or Consultant, or such longer or shorter period
      specified in the Option Agreement, or (ii) the expiration of the term of
      the Option as set forth in the Option Agreement. If, after termination,
      the Optionee does not exercise his or her Option within the time specified
      in the Option Agreement, the Option shall terminate, and the shares
      covered by such Option shall revert to and again become available for
      issuance under the Plan.

      (h) Disability of Optionee. In the event an Optionee's Continuous Status
      as an Employee, Director or Consultant terminates as a result of the
      Optionee's disability, the Optionee may exercise his or her Option (to the
      extent that the Optionee was entitled to exercise it at the date of
      termination), but only within such period of time ending on the earlier of
      (i) the date twelve (12) months following such termination (or such longer
      or shorter period specified in the Option Agreement), or (ii) the
      expiration of the term of the Option as set forth in the Option Agreement.
      If, at the date of termination, the Optionee is not entitled to exercise
      his or her entire Option, the shares covered by the unexercisable portion
      of the Option shall revert to and again become available for issuance
      under the Plan. If, after termination, the Optionee does not exercise his
      or her Option within the time specified herein, the Option shall
      terminate, and the shares covered by such Option shall revert to and again
      become available for issuance under the Plan.

      (i) Death of Optionee. In the event of the death of an Optionee during, or
      within a period specified in the Option after the termination of, the
      Optionee's Continuous Status as an Employee, Director or Consultant, the
      Option may be exercised (to the extent the Optionee was entitled to
      exercise the Option at the date of death) by the

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      Optionee's estate, by a person who acquired the right to exercise the
      Option by bequest or inheritance or by a person designated to exercise the
      option upon the Optionee's death pursuant to subsection 6(d), but only
      within the period ending on the earlier of (i) the date eighteen (18)
      months following the date of death (or such longer or shorter period
      specified in the Option Agreement), or (ii) the expiration of the term of
      such Option as set forth in the Option Agreement. If, at the time of
      death, the Optionee was not entitled to exercise his or her entire Option,
      the shares covered by the unexercisable portion of the Option shall revert
      to and again become available for issuance under the Plan. If, after
      death, the Option is not exercised within the time specified herein, the
      Option shall terminate, and the shares covered by such Option shall revert
      to and again become available for issuance under the Plan.

      (j) Early Exercise. The Option may, but need not, include a provision
      whereby the Optionee may elect at any time while an Employee, Director or
      Consultant to exercise the Option as to any part or all of the shares
      subject to the Option prior to the full vesting of the Option. Any
      unvested shares so purchased may be subject to a repurchase right in favor
      of the Company or to any other restriction the Board determines to be
      appropriate.

      (k) Withholding. To the extent provided by the terms of an Option
      Agreement for an Option, the Participant may satisfy any federal, state,
      local, or other tax withholding obligation relating to the exercise of
      such Option by any of the following means (in addition to the Company's
      right to withhold from any compensation paid to the Optionee by the
      Company) or by a combination of such means: (i) tendering a cash payment;
      (ii) authorizing the Company to withhold shares of common stock from the
      shares of common stock otherwise issuable to the Optionee as a result of
      the exercise of the Option; provided, however, that no shares of common
      stock are withheld with a value exceeding the minimum amount of tax
      required to be withheld by law (or such lesser amount as may be necessary
      to avoid variable award accounting); or (iii) delivering to the Company
      owned and unencumbered shares of common stock.

7.    COVENANTS OF THE COMPANY.

      (a) During the terms of the Options, 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; provided,
      however, that this undertaking shall not require the Company to register
      under the Securities Act either the Plan, any Option 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 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 unless and until such authority is obtained.

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8.    USE OF PROCEEDS FROM STOCK.

Proceeds from the sale of stock pursuant to Options shall constitute general
funds of the Company.

9.    MISCELLANEOUS.

      (a) The Board shall have the power to accelerate the time at which an
      Option may first be exercised or the time during which an Option or any
      part thereof will vest pursuant to subsection 6(e), notwithstanding the
      provisions in the Option stating the time at which it may first be
      exercised or the time during which it will vest.

      (b) Neither an Optionee nor any person to whom an Option is transferred
      under subsection 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.

      (c) Nothing in the Plan or any instrument executed or Option granted
      pursuant thereto shall confer upon any Employee, Director, Consultant or
      Optionee any right to continue in the employ of the Company or any
      Affiliate (or to continue acting as a Director or Consultant) or shall
      affect the right of the Company or any Affiliate to terminate the
      employment or relationship as a Director or Consultant of any Employee,
      Director, or Consultant for any reason, with or without cause.

10.   ADJUSTMENTS UPON CHANGES IN STOCK.

      (a) If any change is made in the stock subject to the Plan, or subject to
      any Option (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 other transaction not involving
      the receipt of consideration), the Plan will be appropriately adjusted in
      the types of securities and maximum number of shares subject to the Plan
      pursuant to subsection 4(a), and the outstanding Options will be
      appropriately adjusted in the types of securities and number of shares and
      price per share of stock subject to such outstanding Options.

      (b) In the event of: (1) a dissolution, liquidation or sale of
      substantially all of the assets of the Company; (2) a merger or
      consolidation in which the Company is not the surviving corporation; or
      (3) 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, then to the extent
      permitted by applicable law: (i) any surviving corporation shall either
      assume any Options outstanding under the Plan or shall substitute similar
      Options for those outstanding under the Plan, or (ii) such Options shall
      terminate to the extent not exercised prior to such event; provided,
      however, that the time during which some or all of such Options may be
      exercised may, at the discretion of the Board, be accelerated to prior to
      such event.

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11.   AMENDMENT OF THE PLAN AND OPTIONS.

      (a) The Board at any time, and from time to time, may amend the Plan.
      However, except as provided in Section 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 modify the Plan in any
      way (including, but not limited to, the modification of the eligibility
      requirements for participation in the Plan) if such modification requires
      stockholder approval in order for the Plan to comply with any NASDAQ or
      securities exchange listing requirements.

      (b) The Board may in its sole discretion submit any other amendment to the
      Plan for stockholder approval.

      (c) It is expressly contemplated that the Board may amend the Plan in any
      respect the Board deems necessary or advisable to provide Optionees with
      the maximum benefits provided or to be provided under the provisions of
      the Code and the regulations promulgated thereunder relating to Options
      and/or to bring the Plan and/or Options granted under it into compliance
      therewith.

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

      (e) The Board at any time, and from time to time, may amend the terms of
      any one or more Options; provided, however, that the rights and
      obligations under any Option shall not be impaired by any 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.

      (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.

13.   EFFECTIVE DATE OF PLAN.

The Plan shall become effective upon adoption by the Board.