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                                                                     EXHIBIT 4.2

                       THE 2002 NEW-HIRE STOCK OPTION PLAN

                                       OF

                             GEN-PROBE INCORPORATED

            Gen-Probe Incorporated, a Delaware corporation, has adopted The 2002
New-Hire Stock Option Plan of Gen-Probe Incorporated (the "Plan"), effective
November 11, 2002, for the benefit of its eligible newly hired Employees.

            The purposes of the Plan are as follows:

            (1) To provide an additional incentive for Employees (as such terms
are defined below) to further the growth, development and financial success of
the Company by personally benefiting through the ownership of Company stock
and/or rights which recognize such growth, development and financial success.

            (2) To enable the Company to obtain and retain the services of
Employees considered essential to the long range success of the Company by
offering them an opportunity to own stock in the Company and/or rights which
will reflect the growth, development and financial success of the Company.

                                   ARTICLE I.

                                   DEFINITIONS

            1.1. General. Whenever the following terms are used in the Plan they
shall have the meanings specified below, unless the context clearly indicates
otherwise.

            1.2. Administrator. "Administrator" shall mean the Committee, except
to the extent the Board has assumed the authority for administration of the Plan
as provided in Section 7.2.

            1.3. Board. "Board" shall mean the Board of Directors of the
Company.

            1.4. Change in Control. "Change in Control" shall mean a change in
ownership or control of the Company effected through any of the following
transactions:

                  (a) any person or related group of persons (other than the
      Company or a person that, prior to such transaction, directly or
      indirectly controls, is controlled by, or is under common control with,
      the Company) directly or indirectly acquires beneficial ownership (within
      the meaning of Rule 13d-3 under the Exchange Act) of securities possessing
      more than fifty percent (50%) of the total combined voting power of the
      Company's outstanding securities pursuant to a tender or exchange offer
      for securities of the Company; or

                  (b) there is a change in the composition of the Board over a
      period of thirty-six (36) consecutive months (or less) such that a
      majority of the Board members

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      (rounded up to the nearest whole number) ceases, by reason of one or more
      proxy contests for the election of Board members, to be comprised of
      individuals who either (i) have been Board members continuously since the
      beginning of such period or (ii) have been elected or nominated for
      election as Board members during such period by at least a majority of the
      Board members described in clause (i) who were still in office at the time
      such election or nomination was approved by the Board; or

                  (c) a merger or consolidation of the Company with any other
      corporation (or other entity), other than a merger or consolidation which
      would result in the voting securities of the Company outstanding
      immediately prior thereto continuing to represent (either by remaining
      outstanding or by being converted into voting securities of the surviving
      entity or another entity) more than 66-2/3% of the combined voting power
      of the voting securities of the Company or such surviving entity
      outstanding immediately after such merger or consolidation; provided,
      however, that a merger or consolidation effected to implement a
      recapitalization of the Company (or similar transaction) in which no
      person acquires more than 25% of the combined voting power of the
      Company's then outstanding voting securities shall not constitute a Change
      in Control; or

                  (d) a plan of complete liquidation of the Company or an
      agreement for the sale or disposition by the Company of all or
      substantially all of the Company's assets.

            1.5. Code. "Code" shall mean the Internal Revenue Code of 1986, as
amended from time to time.

            1.6. Committee. "Committee" shall mean the Compensation Committee of
the Board, or another committee or subcommittee of the Board, appointed as
provided in Section 7.1.

            1.7. Common Stock. "Common Stock" shall mean the common stock of the
Company, par value $0.0001 per share.

            1.8. Company. "Company" shall mean Gen-Probe Incorporated, a
Delaware corporation.

            1.9. Director. "Director" shall mean a member of the Board, whether
such Director is an Employee or a Non-Employee Director.

            1.10. DRO. "DRO" shall mean a domestic relations order as defined by
the Code or Title I of the Employee Retirement Income Security Act of 1974, as
amended, or the rules thereunder.

            1.11. Employee. "Employee" shall mean any officer or other employee
(as defined in accordance with Section 3401(c) of the Code) of the Company, or
of any corporation which is a Subsidiary.

            1.12. Exchange Act. "Exchange Act" shall mean the Securities
Exchange Act of 1934, as amended from time to time.


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            1.13. Fair Market Value. "Fair Market Value" shall mean, as of any
date, the value of the Common Stock determined as follows:

                  (a) If the Common Stock is listed on any established stock
      exchange or traded on The Nasdaq National Market or the Nasdaq SmallCap
      Market, 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 exchange or market (or the exchange or market
      with the greatest volume of trading in the Common Stock) on the last
      market trading day prior to the day of determination, as reported by The
      Nasdaq Stock Market or such other source as the Board deems reliable.

                  (b) In the absence of such markets for the Common Stock, the
      Fair Market Value shall be determined in good faith by the Board.

            1.14. Holder. "Holder" shall mean a person who has been granted an
Option.

            1.15. Independent Director. "Independent Director" shall mean a
member of the Board who is a "non-employee director" for purposes of Rule 16b-3
and who is "independent" within the meaning of NASD Rule 4200.

            1.16. Non-Qualified Stock Option. "Non-Qualified Stock Option" shall
mean an Option not intended to qualify as an incentive stock option within the
meaning of Section 422 of the Code and the regulations promulgated thereunder.

            1.17. Officer. "Officer" shall mean a President, Secretary,
Treasurer, Chairman of the Board, Vice President, Assistant Secretary or
Assistant Treasurer of the Company, as such positions are described in the
Company's Bylaws, any other person designated an "officer" of the Company by the
Board of Directors in accordance with the Company's Bylaws or any person who is
an "officer" within the meaning of Rule 16a-1(f) under the Exchange Act or NASD
Rule 4350(i)(1)(A).

            1.18. Option. "Option" shall mean a Non-Qualified Stock Option
granted under Article IV of the Plan.

            1.19. Option Agreement. "Option Agreement" shall mean a written
agreement executed by an authorized officer of the Company and the Holder, which
shall contain such terms and conditions with respect to an Option, as the
Administrator shall determine, consistent with the Plan.

            1.20. Plan. "Plan" shall mean The 2002 New-Hire Stock Option Plan of
Gen-Probe Incorporated.

            1.21. Rule 16b-3. "Rule 16b-3" shall mean that certain Rule 16b-3
under the Exchange Act, as such Rule may be amended from time to time.

            1.22. Securities Act. "Securities Act" shall mean the Securities Act
of 1933, as amended.


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            1.23. Subsidiary. "Subsidiary" shall mean any corporation in an
unbroken chain of corporations beginning with the Company if each of the
corporations other than the last corporation in the unbroken chain then owns
stock possessing fifty percent (50%) or more of the total combined voting power
of all classes of stock in one of the other corporations in such chain.

            1.24. Substitute Option. "Substitute Option" shall mean an Option
granted under the Plan upon the assumption of, or in substitution for,
outstanding equity awards previously granted by another company or entity, in
connection with a corporate or similar transaction, such as a merger,
combination, consolidation or acquisition of property or stock; provided,
however, that in no event shall the term "Substitute Option" be construed to
refer to an option granted in connection with the cancellation and repricing of
an Option.

            1.25. Termination of Employment. "Termination of Employment" shall
mean the time when the employee-employer relationship between a Holder and the
Company or any Subsidiary is terminated for any reason, with or without cause,
including, but not by way of limitation, a termination by resignation,
discharge, death, disability or retirement; but excluding (a) terminations where
there is a simultaneous reemployment or continuing employment of a Holder by the
Company or any Subsidiary or a parent corporation thereof (within the meaning of
Section 422 of the Code), (b) at the discretion of the Administrator,
terminations which result in a temporary severance of the employee-employer
relationship, and (c) at the discretion of the Administrator, terminations which
are followed by the simultaneous establishment of a consulting relationship by
the Company or a Subsidiary with the former employee. The Administrator, in its
absolute discretion, shall determine the effect of all matters and questions
relating to Termination of Employment, including, but not by way of limitation,
the question of whether a Termination of Employment resulted from a discharge
for cause, and all questions of whether a particular leave of absence
constitutes a Termination of Employment.

                                   ARTICLE II.

                             SHARES SUBJECT TO PLAN

            2.1. Shares Subject to Plan. The shares of stock subject to Options
shall be Common Stock, subject to Section 8.3 of the Plan. The aggregate number
of such shares which may be issued upon exercise of such Options shall not
exceed Two Hundred Thousand (200,000). The shares of Common Stock issuable upon
exercise of such Options may be either previously authorized but unissued shares
or treasury shares.

            2.2. Add-Back of Options. If any Option expires or is canceled
without having been fully exercised, the number of shares of Common Stock
subject to such Option but as to which such Option was not exercised prior to
its expiration or cancellation may again be optioned hereunder, subject to the
limitations of Section 2.1. Furthermore, any shares subject to Options which are
adjusted pursuant to Section 8.3 and become exercisable with respect to shares
of stock of another corporation shall be considered cancelled and may again be
optioned hereunder, subject to the limitations of Section 2.1. Shares of Common
Stock which are delivered by the Holder or withheld by the Company upon the
exercise of any Option under the Plan, in payment of the exercise price thereof
or tax withholding thereon, may again be optioned, granted or awarded hereunder,
subject to the limitations of Section 2.1.


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                                  ARTICLE III.

                               GRANTING OF OPTIONS

            3.1. Option Agreement. Each Option shall be evidenced by an Option
Agreement.

            3.2. Limitations Applicable to Section 16 Persons. Notwithstanding
any other provision of the Plan, the Plan, and any Option granted to any
individual who is then subject to Section 16 of the Exchange Act, shall be
subject to any additional limitations set forth in any applicable exemptive rule
under Section 16 of the Exchange Act (including any amendment to Rule 16b-3 of
the Exchange Act) that are requirements for the application of such exemptive
rule. To the extent permitted by applicable law, the Plan and the Options
granted hereunder shall be deemed amended to the extent necessary to conform to
such applicable exemptive rule.

            3.3. At-Will Employment. Nothing in the Plan or in any Option
Agreement hereunder shall confer upon any Holder any right to continue in the
employ of the Company or any Subsidiary or shall interfere with or restrict in
any way the rights of the Company and any Subsidiary to discharge any Holder at
any time for any reason whatsoever, with or without cause, except to the extent
expressly provided otherwise in a written employment agreement between the
Holder and the Company and any Subsidiary.

                                   ARTICLE IV.

                        GRANTING OF OPTIONS TO EMPLOYEES

            4.1. Eligibility. Notwithstanding anything herein to the contrary,
only newly hired Employees (including Employees who will become Officers or
Directors of the Company) who have not previously been employed by the Company
and with respect to whom Options are to be granted as an inducement material to
such Employees' entering into employment with the Company shall be eligible to
receive grants of Options under this Plan. All grants shall be made at the
discretion of the Committee or a majority of the Company's Independent
Directors, and no person shall be entitled to a grant of an Option as a matter
of right.

            4.2. Granting of Options to Employees.

                  (a) The Committee shall from time to time, in its absolute
      discretion, and subject to applicable limitations of the Plan:

                        (i) Select from among the newly hired Employees such of
            them as in its opinion should be granted Options;

                        (ii) determine the number of shares of Common Stock
            to be subject to such Options granted to the selected Employees;

                        (iii) Determine the terms and conditions of such
            Options, consistent with the Plan.


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                  (b) Upon the selection of an Employee to be granted an Option,
      the Committee shall instruct the Secretary of the Company to issue the
      Option and may impose such conditions on the grant of the Option as it
      deems appropriate, and the Committee shall authorize one or more of the
      officers of the Company to prepare, execute and deliver the Option
      Agreement with respect to such Option.

            4.3. Options in Lieu of Cash Compensation. Options may be granted
under the Plan to Employees in lieu of cash bonuses which would otherwise be
payable to such Employees pursuant to such policies which may be adopted by the
Administrator from time to time.

                                   ARTICLE V.

                                TERMS OF OPTIONS

            5.1. Option Price. The price per share of the shares of Common Stock
subject to each Option granted to Employees shall be set by the Committee;
provided, however, that such price shall be no less than 100% of the Fair Market
Value of a share of Common Stock on the date the Option is granted.

            5.2. Option Term. The term of an Option granted to an Employee shall
be set by the Committee in its absolute discretion; provided, however, that the
term shall not be more than ten (10) years from the date the Option is granted.
The Committee may extend the term of any outstanding Option in connection with
any Termination of Employment of the Holder, or amend any other term or
condition of such Option relating to such a termination.

            5.3. Option Vesting

                  (a) The period during which the right to exercise, in whole or
      in part, an Option granted to an Employee vests in the Holder shall be set
      by the Committee, and the Committee may determine that an Option may not
      be exercised in whole or in part for a specified period after it is
      granted. At any time after grant of an Option, the Committee may, in its
      absolute discretion and subject to whatever terms and conditions it
      selects, accelerate the period during which an Option granted to an
      Employee vests and becomes exercisable.

                  (b) No portion of an Option granted to an Employee which is
      unexercisable at Termination of Employment shall thereafter become
      exercisable, except as may be otherwise provided by the Committee either
      in the Option Agreement or by action of the Committee following the grant
      of the Option.

            5.4. Substitute Awards. Notwithstanding the foregoing provisions of
this Article V to the contrary, in the case of an Option that is a Substitute
Award, the price per share of the shares subject to such Option may be less than
the Fair Market Value per share on the date of grant, provided, that the excess
of:

                  (a) the aggregate Fair Market Value (as of the date such
      Substitute Award is granted) of the shares subject to the Substitute
      Award; over


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                  (b) the aggregate exercise price thereof;

                      does not exceed the excess of:

                  (c) the aggregate fair market value (as of the time
      immediately preceding the transaction giving rise to the Substitute Award,
      such fair market value to be determined by the Administrator) of the
      shares of the predecessor entity that were subject to the grant assumed or
      substituted for by the Company; over

                  (d) the aggregate exercise price of such shares.

            5.5. Restrictions on Common Stock. The Administrator may, in its
sole discretion, provide under the terms of an Option that shares of Common
Stock purchased upon exercise of such Option shall be subject to repurchase from
the Holder by the Company, or shall be subject to such restrictions as the
Administrator shall provide, which restrictions may include, without limitation,
restrictions concerning voting rights and transferability and restrictions based
on duration of employment with the Company and the Subsidiaries, Company
performance and individual performance; provided, however, that, by action taken
after the Common Stock is purchased upon exercise of the Option, the
Administrator may, on such terms and conditions as it may determine to be
appropriate, terminate the Company's repurchase right or remove any or all of
the restrictions imposed by the terms of the Option Agreement. The Company's
right to repurchase the Common Stock from the Holder then subject to the right
shall provide that immediately upon a Termination of Employment and for such
period as the Administrator shall determine, the Company shall have the right to
purchase the Common Stock at a price per share equal to the price paid by the
Holder for such Common Stock, or such other price as is determined by the
Administrator; provided, however, that, in the event of a Change in Control,
such right of repurchase shall terminate immediately prior to the effective date
of such Change in Control. Shares of Common Stock purchased upon the exercise of
an Option may not be sold, transferred or encumbered until any repurchase right
and any and all restrictions are terminated or expire. The Secretary of the
Company or such other escrow holder as the Administrator may appoint shall
retain physical custody of each certificate representing such shares of Common
Stock until the repurchase right and any and all of the restrictions imposed
under the Option Agreement with respect to the shares evidenced by such
certificate terminate, expire or shall have been removed. In order to enforce
the restrictions imposed upon shares of Common Stock hereunder, the
Administrator shall cause a legend or legends to be placed on certificates
representing all shares of Common Stock that are still subject to any repurchase
right or restrictions under Option Agreements, which legend or legends shall
make appropriate reference to the conditions imposed thereby. If a Holder makes
an election under Section 83(b) of the Code, or any successor section thereto,
to be taxed with respect to the Common Stock as of the date of transfer of the
Common Stock rather than as of the date or dates upon which the Holder would
otherwise be taxable under Section 83(a) of the Code, the Holder shall deliver a
copy of such election to the Company immediately after filing such election with
the Internal Revenue Service.


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                                   ARTICLE VI.

                               EXERCISE OF OPTIONS

            6.1. Partial Exercise. An exercisable Option may be exercised in
whole or in part. However, an Option shall not be exercisable with respect to
fractional shares and the Administrator may require that, by the terms of the
Option, a partial exercise be with respect to a minimum number of shares.

            6.2. Manner of Exercise. All or a portion of an exercisable Option
shall be deemed exercised upon delivery of all of the following to the Secretary
of the Company or his office:

                  (a) A written notice complying with the applicable rules
      established by the Administrator stating that the Option, or a portion
      thereof, is exercised. The notice shall be signed by the Holder or other
      person then entitled to exercise the Option or such portion of the Option;

                  (b) Such representations and documents as the Administrator,
      in its absolute discretion, deems necessary or advisable to effect
      compliance with all applicable provisions of the Securities Act and any
      other federal or state securities laws or regulations. The Administrator
      may, in its absolute discretion, also take whatever additional actions it
      deems appropriate to effect such compliance including, without limitation,
      placing legends on share certificates and issuing stop-transfer notices to
      agents and registrars;

                  (c) In the event that the Option shall be exercised pursuant
      to Section 8.1 by any person or persons other than the Holder, appropriate
      proof of the right of such person or persons to exercise the Option; and

                  (d) Full cash payment to the Secretary of the Company for the
      shares with respect to which the Option, or portion thereof, is exercised.
      However, the Administrator, may in its sole and absolute discretion (i)
      allow a delay in payment up to thirty (30) days from the date the Option,
      or portion thereof, is exercised; (ii) allow payment, in whole or in part,
      through the delivery of shares of Common Stock which have been owned by
      the Holder for at least six months, duly endorsed for transfer to the
      Company with a Fair Market Value on the date of delivery equal to the
      aggregate exercise price of the Option or exercised portion thereof; (iii)
      allow payment, in whole or in part, through the surrender of shares of
      Common Stock then issuable upon exercise of the Option having a Fair
      Market Value on the date of Option exercise equal to the aggregate
      exercise price of the Option or exercised portion thereof; (iv) allow
      payment, in whole or in part, through the delivery of a notice that the
      Holder has placed a market sell order with a broker with respect to shares
      of Common Stock then issuable upon exercise of the Option, and that the
      broker has been directed to pay a sufficient portion of the net proceeds
      of the sale to the Company in satisfaction of the Option exercise price;
      provided that payment of such proceeds is then made to the Company upon
      settlement of such sale;


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      or (v) allow payment through any combination of the consideration provided
      in the foregoing subparagraphs (ii), (iii) and (iv).

            6.3. Conditions to Issuance of Stock Certificates. The Company shall
not be required to issue or deliver any certificate or certificates for shares
of stock purchased upon the exercise of any Option or portion thereof prior to
fulfillment of all of the following conditions:

                  (a) The admission of such shares to listing on all stock
      exchanges on which such class of stock is then listed;

                  (b) The completion of any registration or other qualification
      of such shares under any state or federal law, or under the rulings or
      regulations of the Securities and Exchange Commission or any other
      governmental regulatory body which the Administrator shall, in its
      absolute discretion, deem necessary or advisable;

                  (c) The obtaining of any approval or other clearance from any
      state or federal governmental agency which the Administrator shall, in its
      absolute discretion, determine to be necessary or advisable;

                  (d) The lapse of such reasonable period of time following the
      exercise of the Option as the Administrator may establish from time to
      time for reasons of administrative convenience; and

                  (e) The receipt by the Company of full payment for such
      shares, including payment of any applicable withholding tax, which in the
      discretion of the Administrator may be in the form of consideration used
      by the Holder to pay for such shares under Section 6.2(d).

            6.4. Rights as Stockholders. Holders shall not be, nor have any of
the rights or privileges of, stockholders of the Company in respect of any
shares purchasable upon the exercise of any part of an Option unless and until
certificates representing such shares have been issued by the Company to such
Holders.

            6.5. Ownership and Transfer Restrictions. The Administrator, in its
absolute discretion, may impose such restrictions on the ownership and
transferability of the shares purchasable upon the exercise of an Option as it
deems appropriate. Any such restriction shall be set forth in the respective
Option Agreement and may be referred to on the certificates evidencing such
shares.

            6.6. Additional Limitations on Exercise of Options. Holders may be
required to comply with any timing or other restrictions with respect to the
settlement or exercise of an Option, including a window-period limitation, as
may be imposed in the discretion of the Administrator.


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                                  ARTICLE VII.

                                 ADMINISTRATION

            7.1. Committee. The Committee shall be the Compensation Committee of
the Board (or another committee or a subcommittee of the Board assuming the
functions of the Committee under the Plan), and the Compensation Committee (or
other committee or subcommittee) shall consist solely of two or more
Non-Employee Directors appointed by and holding office at the pleasure of the
Board. Appointment of Committee members shall be effective upon acceptance of
appointment. Committee members may resign at any time by delivering written
notice to the Board. Vacancies in the Committee may be filled by the Board.

            7.2. Duties and Powers of Committee. It shall be the duty of the
Committee to conduct the general administration of the Plan in accordance with
its provisions. The Committee shall have the power to interpret the Plan and the
Option Agreements, and to adopt such rules for the administration,
interpretation, and application of the Plan as are consistent therewith, to
interpret, amend or revoke any such rules and to amend any Option Agreement
provided that the rights or obligations of the Holder of the Option that is the
subject of any such Option Agreement are not affected adversely. In its absolute
discretion, the Board may at any time and from time to time assume any and all
rights and duties of the Committee under the Plan; provided that grants of
Options may be made only by the Committee or by a majority of the Company's
Independent Directors.

            7.3. Majority Rule; Unanimous Written Consent. The Committee shall
act by a majority of its members in attendance at a meeting at which a quorum is
present or by a memorandum or other written instrument signed by all members of
the Committee.

            7.4. Compensation; Professional Assistance; Good Faith Actions.
Members of the Committee shall receive such compensation, if any, for their
services as members as may be determined by the Board. All expenses and
liabilities which members of the Committee incur in connection with the
administration of the Plan shall be borne by the Company. The Committee may,
with the approval of the Board, employ attorneys, consultants, accountants,
appraisers, brokers, or other persons. The Committee, the Company and the
Company's officers and directors shall be entitled to rely upon the advice,
opinions or valuations of any such persons. All actions taken and all
interpretations and determinations made by the Committee or the Board in good
faith shall be final and binding upon all Holders, the Company and all other
interested persons. No members of the Committee or Board shall be personally
liable for any action, determination or interpretation made in good faith with
respect to the Plan or Options, and all members of the Committee and the Board
shall be fully protected by the Company in respect of any such action,
determination or interpretation.

                                  ARTICLE VIII.

                            MISCELLANEOUS PROVISIONS

            8.1. Not Transferable. No Option under the Plan may be sold,
pledged, assigned or transferred in any manner other than by will or the laws of
descent and distribution


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or, subject to the consent of the Administrator, pursuant to a DRO, unless and
until such Option has been exercised, or the shares underlying such Option have
been issued, and all restrictions applicable to such shares have lapsed. No
Option or interest or right therein shall be liable for the debts, contracts or
engagements of the Holder or his successors in interest or shall be subject to
disposition by transfer, alienation, anticipation, pledge, encumbrance,
assignment or any other means whether such disposition be voluntary or
involuntary or by operation of law by judgment, levy, attachment, garnishment or
any other legal or equitable proceedings (including bankruptcy), and any
attempted disposition thereof shall be null and void and of no effect, except to
the extent that such disposition is permitted by the preceding sentence.

            During the lifetime of the Holder, only he may exercise an Option
(or any portion thereof) granted to him under the Plan, unless it has been
disposed of with the consent of the Administrator pursuant to a DRO. After the
death of the Holder, any exercisable portion of an Option may, prior to the time
when such portion becomes unexercisable under the Plan or the applicable Option
Agreement, be exercised by his personal representative or by any person
empowered to do so under the deceased Holder's will or under the then applicable
laws of descent and distribution.

            Notwithstanding the foregoing provisions of this Section 8.1, the
Administrator, in its sole discretion, may determine to grant a Non-Qualified
Stock Option which, by its terms as set forth in the applicable Option
Agreement, may be transferred by the Holder, in writing and with prior written
notice to the Administrator, to any one or more Permitted Transferees (as
defined below), subject to the following terms and conditions: (a) a
Non-Qualified Stock Option transferred to a Permitted Transferee shall not be
assignable or transferable by the Permitted Transferee other than by will or the
laws of descent and distribution; (b) any Non-Qualified Stock Option which is
transferred to a Permitted Transferee shall continue to be subject to all the
terms and conditions of the Non-Qualified Stock Option as applicable to the
original Holder (other than the ability to further transfer the Non-Qualified
Stock Option); and (c) the Holder and the Permitted Transferee shall execute any
and all documents requested by the Administrator, including, without limitation,
documents to: (i) confirm the status of the transferee as a Permitted
Transferee, (ii) satisfy any requirements for an exemption for the transfer
under applicable federal and state securities laws and (iii) evidence the
transfer. For purposes of this Section, "Permitted Transferee" shall mean, with
respect to a Holder, any child, stepchild, grandchild, parent, stepparent,
grandparent, spouse, former spouse, sibling, niece, nephew, mother-in-law,
father-in-law, daughter-in-law, brother-in-law, or sister-in-law, including
adoptive relationships, any person sharing the Holder's household (other than a
tenant or employee), a trust in which these persons (or the Holder) control the
management of assets, and any other entity in which these persons (or the
Holder) owns more than fifty percent (50%) of the voting interests, or any other
transferee specifically approved by the Administrator after taking into account
any state or federal tax or securities laws applicable to transferable
Non-Qualified Stock Options.

            8.2. Amendment, Suspension or Termination of the Plan. Except as
otherwise provided in this Section 8.2, the Plan may be wholly or partially
amended or otherwise modified, suspended or terminated at any time or from time
to time by the Board. No amendment, suspension or termination of the Plan shall,
without the consent of the Holder alter or impair any rights or obligations
under any Option theretofore granted or awarded, unless the Option itself


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otherwise expressly so provides. No Options may be granted or awarded during any
period of suspension or after termination of the Plan, and in no event may any
Option be granted under the Plan after the expiration of ten years from the date
the Plan is adopted by the Board.

            8.3. Changes in Common Stock or Assets of the Company, Acquisition
or Liquidation of the Company and Other Corporate Events.

                  (a) Subject to Section 8.3(d), in the event that the
      Administrator determines that any dividend or other distribution (whether
      in the form of cash, Common Stock, other securities, or other property),
      recapitalization, reclassification, stock split, reverse stock split,
      reorganization, merger, consolidation, split-up, spin-off, combination,
      repurchase, liquidation, dissolution, or sale, transfer, exchange or other
      disposition of all or substantially all of the assets of the Company, or
      exchange of Common Stock or other securities of the Company, issuance of
      warrants or other rights to purchase Common Stock or other securities of
      the Company, or other similar corporate transaction or event, in the
      Administrator's sole discretion, affects the Common Stock such that an
      adjustment is determined by the Administrator to be appropriate in order
      to prevent dilution or enlargement of the benefits or potential benefits
      intended to be made available under the Plan or with respect to an Option,
      then the Administrator shall, in such manner as it may deem equitable,
      adjust any or all of:

                        (i) the number and kind of shares of Common Stock (or
            other securities or property) with respect to which Options may be
            granted (including, but not limited to, adjustments of the
            limitations in Section 2.1 on the maximum number and kind of shares
            which may be issued),

                        (ii)  the number and kind of shares of Common Stock (or
            other securities or property) subject to outstanding Options, and

                        (iii) the exercise price with respect to any Option.

                  (b) Subject to Sections 8.3(d) and 8.4, in the event of any
      transaction or event described in Section 8.3(a) or any unusual or
      nonrecurring transactions or events affecting the Company, any affiliate
      of the Company, or the financial statements of the Company or any
      affiliate, or of changes in applicable laws, regulations, or accounting
      principles, the Administrator, in its sole and absolute discretion, and on
      such terms and conditions as it deems appropriate, either by the terms of
      the Option or by action taken prior to the occurrence of such transaction
      or event (any such action applied to Employees and former Employees to be
      applied uniformly) and either automatically or upon the Holder's request,
      is hereby authorized to take any one or more of the following actions
      whenever the Administrator determines that such action is appropriate in
      order to prevent dilution or enlargement of the benefits or potential
      benefits intended to be made available under the Plan or with respect to
      any Option under the Plan, to facilitate such transactions or events or to
      give effect to such changes in laws, regulations or principles:

                        (i)   to provide for either the cancellation of any such


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<PAGE>

            Option for an amount of cash equal to the amount that could have
            been attained upon the exercise of such Option or realization of the
            Holder's rights had such Option been currently exercisable or fully
            vested, or the replacement of such Option with other rights or
            property selected by the Administrator in its sole discretion;

                        (ii) to provide that the Option cannot vest or be
            exercised after such event;

                        (iii) to provide that such Option shall be exercisable
            as to all shares covered thereby, notwithstanding anything to the
            contrary in Section 5.3 or the provisions of such Option;

                        (iv) to provide that such Option be assumed by the
            successor or survivor corporation, or a parent or subsidiary
            thereof, or shall be substituted for by similar options, rights or
            awards covering the stock of the successor or survivor corporation,
            or a parent or subsidiary thereof, with appropriate adjustments as
            to the number and kind of shares and prices;

                        (v) to make adjustments in the number and type of shares
            of Common Stock (or other securities or property) subject to
            outstanding Options and/or in the terms and conditions of (including
            the exercise price), and the criteria included in, outstanding
            Options and Options which may be granted in the future; and

                        (vi) to provide that, for a specified period of time
            prior to such event, the restrictions imposed under an Option
            Agreement upon some or all shares of Common Stock may be terminated
            and some or all shares of such Common Stock may cease to be subject
            to repurchase after such event.

                  (c) Subject to Sections 8.3(d), 3.2 and 3.3, the Administrator
      may, in its discretion, include such further provisions and limitations in
      any Option, Option Agreement or certificate, as it may deem equitable and
      in the best interests of the Company.

                  (d) No adjustment or action described in this Section 8.3 or
      in any other provision of the Plan shall be authorized to the extent such
      adjustment or action would result in short-swing profits liability under
      Section 16 or violate the exemptive conditions of Rule 16b-3 unless the
      Administrator determines that the Option is not to comply with such
      exemptive conditions. The number of shares of Common Stock subject to any
      Option shall always be rounded to the next whole number.

                  (e) The existence of the Plan, the Option Agreement and the
      Options granted hereunder shall not affect or restrict in any way the
      right or power of the Company or the stockholders of the Company to make
      or authorize any adjustment, recapitalization, reorganization or other
      change in the Company's capital structure or its


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<PAGE>

      business, any merger or consolidation of the Company, any issue of stock
      or of options, warrants or rights to purchase stock or of bonds,
      debentures, preferred or prior preference stocks whose rights are superior
      to or affect the Common Stock or the rights thereof or which are
      convertible into or exchangeable for Common Stock, or the dissolution or
      liquidation of the Company, or any sale or transfer of all or any part of
      its assets or business, or any other corporate act or proceeding, whether
      of a similar character or otherwise.

            8.4. Change in Control. Notwithstanding any other provision of the
Plan, in the event of a Change in Control, each outstanding Option shall,
immediately prior to the effective date of the Change in Control, automatically
become fully exercisable for all of the shares of Common Stock at the time
subject to such Option and may be exercised for any or all of those shares as
fully-vested shares of Common Stock.

            8.5. Tax Withholding. The Company shall be entitled to require
payment in cash or deduction from other compensation payable to each Holder of
any sums required by federal, state or local tax law to be withheld with respect
to the issuance, vesting, exercise or payment of any Option. The Administrator
may in its discretion and in satisfaction of the foregoing requirement allow
such Holder to elect to have the Company withhold shares of Common Stock
otherwise issuable under such Option (or allow the return of shares of Common
Stock) having a Fair Market Value equal to the sums required to be withheld.
Notwithstanding any other provision of the Plan, the number of shares of Common
Stock which may be withheld with respect to the issuance, vesting, exercise or
payment of any Option (or which may be repurchased from the Holder of such
Option within six months after such shares of Common Stock were acquired by the
Holder from the Company) in order to satisfy the Holder's federal and state
income and payroll tax liabilities with respect to the issuance, vesting,
exercise or payment of the Option shall be limited to the number of shares which
have a Fair Market Value on the date of withholding or repurchase equal to the
aggregate amount of such liabilities based on the minimum statutory withholding
rates for federal and state tax income and payroll tax purposes that are
applicable to such supplemental taxable income.

            8.6. Forfeiture Provisions. Subject to the limitations of applicable
law, pursuant to its general authority to determine the terms and conditions
applicable to Options under the Plan, the Administrator shall have the right to
provide, in the terms of Options made under the Plan, or to require a Holder to
agree by separate written instrument, that if (a)(i) the Holder at any time, or
during a specified time period, engages in any activity in competition with the
Company, or which is inimical, contrary or harmful to the interests of the
Company, as further defined by the Administrator or (ii) the Holder incurs a
Termination of Employment for cause, then (b) (i) any proceeds, gains or other
economic benefit actually or constructively received by the Holder upon any
exercise of the Option, or upon the receipt or resale of any Common Stock
underlying the Option, must be paid to the Company, and (ii) the Option shall
terminate and any unexercised portion of the Option (whether or not vested)
shall be forfeited.

            8.7. Effect of Plan upon Options and Compensation Plans. The
adoption of the Plan shall not affect any other compensation or incentive plans
in effect for the Company or any Subsidiary. Nothing in the Plan shall be
construed to limit the right of the Company (a) to establish any other forms of
incentives or compensation for Employees of the Company or any


                                       14
<PAGE>

Subsidiary or (b) to grant or assume options or other rights or awards otherwise
than under the Plan in connection with any proper corporate purpose including
but not by way of limitation, the grant or assumption of options in connection
with the acquisition by purchase, lease, merger, consolidation or otherwise, of
the business, stock or assets of any corporation, partnership, limited liability
company, firm or association.

            8.8. Compliance with Laws. The Plan, the granting and vesting of
Options under the Plan and the issuance and delivery of shares of Common Stock
and the payment of money under the Plan or under Options granted hereunder are
subject to compliance with all applicable federal and state laws, rules and
regulations (including but not limited to state and federal securities law and
federal margin requirements) and to such approvals by any listing, regulatory or
governmental authority as may, in the opinion of counsel for the Company, be
necessary or advisable in connection therewith. Any securities delivered under
the Plan shall be subject to such restrictions, and the person acquiring such
securities shall, if requested by the Company, provide such assurances and
representations to the Company as the Company may deem necessary or desirable to
assure compliance with all applicable legal requirements. To the extent
permitted by applicable law, the Plan and Options granted or awarded hereunder
shall be deemed amended to the extent necessary to conform to such laws, rules
and regulations.

            8.9. Inability to Obtain Authority. The inability of the Company to
obtain authority from any regulatory body having jurisdiction, which authority
is deemed by the Company's counsel to be necessary to the lawful issuance and
sale of share of Common Stock hereunder, shall relieve the Company of any
liability in respect of the failure to issue or sell such shares of Common Stock
as to which such requisite authority shall not have been obtained.

            8.10. Reservation of Shares. The Company, during the term of this
Plan, shall at all times reserve and keep available such number of shares of
Common Stock as shall be sufficient to satisfy the requirements of the Plan.

            8.11. Investment Intent. The Company may require a Holder or other
person purchasing shares of Common Stock, as a condition of exercising or
acquiring Common Stock under any Option, to give written assurances satisfactory
to the Company as to the Holder's or other person's knowledge and experience in
financial and business matters and/or to employ a representative reasonably
satisfactory to the Company who is knowledgeable and experienced in financial
and business matters and that such Holder or person is capable of evaluating,
alone or together with the representative, the merits and risks of exercising
the Option; and to give written assurances satisfactory to the Company stating
that the person is acquiring the stock subject to the Option for such Holder or
person's own account and not with any present intention of selling or otherwise
distributing the Common Stock. The foregoing requirements, and any assurances
given pursuant to such requirements, shall be inoperative if the issuance of the
shares upon the exercise or acquisition of Common Stock under the applicable
Option has been registered under a then currently effective registration
statement under the Securities Act, or 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.


                                       15
<PAGE>

            8.12. Titles. Titles are provided herein for convenience only and
are not to serve as a basis for interpretation or construction of the Plan.

            8.13. Governing Law. The Plan and any agreements hereunder shall be
administered, interpreted and enforced under the internal laws of the State of
California without regard to conflicts of laws thereof.

            8.14. Compliance with NASD Rules. The Plan has been designed to
permit grants of Options to newly hired Employees without shareholder approval
in accordance with the express exceptions to NASD Rule 4350(i) and shall be
interpreted and administered in a manner consistent with such intent.

                                          * * *

            I hereby certify that the foregoing Plan was duly adopted by the
Board of Directors of Gen-Probe Incorporated on November 11, 2002.

            Executed on this 11th day of November, 2002.


                                          /s/ R. William Bowen
                                          ------------------------------
                                          R. William Bowen
                                          Secretary


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