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                                                                   Exhibit 10.70

                             GEN-PROBE INCORPORATED

                          EMPLOYEE STOCK PURCHASE PLAN
 (adopted by Board of Directors on May 3, 2003 and the Compensation Committee on
                                 April 2, 2003)
                    (adopted by Stockholders on May 29, 2003)

                  Gen-Probe Incorporated, a Delaware corporation (the
"Company"), hereby adopts the Gen-Probe Incorporated Employee Stock Purchase
Plan (the "Plan"), effective as of May 30, 2003.

                  The purposes of the Plan are as follows:

                           (1)      To assist eligible employees of the Company
         and its Designated Subsidiary Corporations (as defined below) in
         acquiring stock ownership in the Company pursuant to a plan which is
         intended to qualify as an "employee stock purchase plan," within the
         meaning of Section 423(b) of the Code (as defined below).

                           (2)      To encourage such employees to remain in the
         employment of the Company and its Subsidiary Corporations.

         1.       DEFINITIONS. Whenever any of the following terms is used in
the Plan with the first letter or letters capitalized, it shall have the
following meaning unless context clearly indicates to the contrary (such
definitions to be equally applicable to both the singular and the plural forms
of the terms defined):

                  (a)      "Account" shall mean the account established for an
Eligible Employee under the Plan with respect to an Offering Period.

                  (b)      "Agent" shall mean the brokerage firm, bank or other
financial institution, entity or person(s) engaged, retained, appointed or
authorized to act as the agent of the Company or an Employee with regard to the
Plan.

                  (c)      "Authorization" shall mean an Eligible Employee's
payroll deduction authorization with respect to an Offering Period provided by
such Eligible Employee in accordance with Section 3(b).

                  (d)      "Base Compensation" shall mean the (i) base salary
payable to an Eligible Employee by the Company during such individual's period
of participation in one or more Offering Periods under the Plan, plus (ii) all
overtime payments, bonuses, commissions, current profit-sharing distributions
and other incentive compensation payments. Such Base Compensation shall be
calculated before deduction of (A) any income or employment tax withholdings, or
(B) any pre-tax contributions made by the Company to any Code Section 401(k)
salary deferral plan or any Code Section 125 cafeteria benefit program now or
hereafter established by the Company. However, Base Compensation shall not
include any contributions (other than Code Section 401(k) or Code Section 125
contributions) made on the Eligible Employee's behalf by the Company to any
employee benefit or welfare plan now or hereafter established.

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

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

                  (g)      "Committee" means the committee of the Board
appointed to administer the Plan pursuant to Section 13.

                  (h)      "Company" means Gen-Probe Incorporated, a Delaware
                           corporation.

                  (i)      "Date of Exercise" of any Option means the date on
which such Option is exercised, which shall be the last day of the Offering
Period with respect to which the Option was granted, in accordance with Section
4(a) (except as provided in Section 9).

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                  (j)      "Date of Grant" of any Option means the date on which
such Option is granted, which shall be the first day of the Offering Period with
respect to which the Option was granted, in accordance with Section 3(a).

                  (k)      "Designated Subsidiary Corporation" means any
Subsidiary Corporation designated by the Board in accordance with Section 14.

                  (l)      "Eligible Employee" means an Employee of the Company
or any Designated Subsidiary Corporation who does not, immediately after the
Option is granted, own (directly or through attribution) stock possessing five
percent (5%) or more of the total combined voting power or value of all classes
of Stock or other stock of the Company, a Parent Corporation or a Subsidiary
Corporation (as determined under Section 423(b)(3) of the Code). The rules of
Section 424(d) of the Code with regard to the attribution of stock ownership
shall apply in determining the stock ownership of an individual, and stock that
an Employee may purchase under outstanding options shall be treated as stock
owned by the Employee. During a leave of absence meeting the requirements of
Treasury Regulation Section 1.421-7(h)(2), an individual shall be treated as an
Employee of the Company or Subsidiary Corporation employing such individual
immediately prior to such leave. Notwithstanding the foregoing, an Employee
whose customary employment is for 20 hours or less per week or for less than 5
months in any calendar year shall not be Eligible an Employee.

                  (m)      "Employee" shall mean an individual who renders
services to the Company or a Subsidiary Corporation in the status of an
"employee" within the meaning of Code Section 3401(c). "Employee" shall not
include any director of the Company or a Subsidiary Corporation who does not
render services to the Company or a Subsidiary Corporation in the status of an
"employee" within the meaning of Code Section 3401(c).

                  (n)      "Offering Period" shall mean each six-month period
commencing on any March 1 and September 1 on or after May 30, 2003; provided,
however, that the first Offering Period under the Plan shall commence on June
20, 2003 and end on the last trading day on or before September 1, 2003. Options
shall be granted on the Date of Grant and exercised on the Date of Exercise, as
provided in Sections 3(a) and 4(a), respectively.

                  (o)      "Option" means an option to purchase shares of Stock
granted under the Plan to an Eligible Employee in accordance with Section 3(a).

                  (p)      "Option Price" means the option price per share of
Stock determined in accordance with Section 4(b).

                  (q)      "Parent Corporation" means any corporation, other
than the Company, in an unbroken chain of corporations ending with the Company
if, at the time of the granting of the Option, each of the corporations other
than the Company owns stock possessing 50% or more of the total combined voting
power of all classes of stock in one of the other corporations in such chain.

                  (r)      "Payday" means the regular and recurring established
day for payment of Base Compensation to an Employee of the Company or any
Subsidiary Corporation.

                  (s)      "Plan" means the Gen-Probe Incorporated Employee
Stock Purchase Plan.

                  (t)      "Stock" means the shares of the Company's common
stock, $0.0001 par value.

                  (u)      "Subsidiary Corporation" means any corporation, other
than the Company, in an unbroken chain of corporations beginning with the
Company if, at the time of the granting of the Option, each of the corporations
other than the last corporation in an unbroken chain owns stock possessing 50%
or more of the total combined voting power of all classes of stock in one of the
other corporations in such chain.

         2.       STOCK SUBJECT TO THE PLAN. Subject to the provisions of
Section 9 hereof (relating to adjustments upon changes in the Stock) and Section
12 hereof (relating to amendments of the Plan), the

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maximum number of shares of Stock which shall be made available for sale under
the Plan shall be 1,000,000(1) shares.

         3.       GRANT OF OPTIONS.

                  (a)      Option Grants. The Company shall grant Options under
the Plan to all Eligible Employees in successive Offering Periods until the
earlier of: (i) the date on which the number of shares of Stock available under
the Plan have been sold or (ii) the date on which the Plan is suspended or
terminates. Each Employee who is an Eligible Employee on the first day of an
Offering Period shall be granted an Option with respect to such Offering Period.
The Date of Grant of such an Option shall be the first day of the Offering
Period with respect to which such Option was granted. Each Option shall expire
on the Date of Exercise immediately after the automatic exercise of the Option
in accordance with Section 4(a), unless such Option terminates earlier in
accordance with Section 5, 6 or 9. The number of shares of Stock subject to an
Eligible Employee's Option shall equal the cumulative payroll deductions
authorized by such Eligible Employee in accordance with subsection (b) of this
Section 3 for the Option Period (if any), divided by the Option Price; provided,
however, that the number of shares of Stock subject to such Option shall not
exceed 200,000(2) shares; and, provided, further, that the number of shares of
Stock subject to such Option shall not exceed the number determined in
accordance with subsection (c). The Company shall not grant an Option with
respect to an Offering Period to any individual who is not an Eligible Employee
on the first day of such Offering Period.

                  (b)      Election to Participate; Payroll Deduction
Authorization. Except as provided in subsection (d), an Eligible Employee shall
participate in the Plan only by means of payroll deduction. Each Eligible
Employee who elects to participate in the Plan with respect to an Offering
Period shall deliver to the Company, not later than ten (10) days before the
first day of the Offering Period, a completed and executed written payroll
deduction authorization in a form prepared by the Committee (the
"Authorization"). An Eligible Employee's Authorization shall give notice of such
Eligible Employee's election to participate in the Plan for the next following
Offering Period (and subsequent Offering Periods) and shall designate a whole
percentage of such Eligible Employee's Base Compensation to be withheld by the
Company or the Designated Subsidiary Corporation employing such Eligible
Employee on each Payday during the Offering Period. An Eligible Employee may
designate any whole percentage of Base Compensation which is not to be less than
one percent (1%) and not more than fifteen percent (15%). An Eligible Employee's
Base Compensation payable during an Offering Period shall be reduced each Payday
through payroll deduction in an amount equal to the percentage specified in the
Authorization, and such amount shall be credited to such Eligible Employee's
Account under the Plan. An Eligible Employee may change the percentage of Base
Compensation designated in the Authorization, subject to the limits of this
subsection (b), or may suspend the Authorization, at any time during the
Offering Period, provided, that any such change or suspension shall become
effective not later than ten (10) days after receipt by the Company. Any
Authorization shall remain in effect for each subsequent Offering Period, unless
the Eligible Employee submits a new Authorization pursuant to this subsection
(b), withdraws from the Plan pursuant to Section 5, ceases to be an Eligible
Employee as defined in Section 1(l) or terminates employment as provided in
Section 6.

                  (c)      $25,000 Limitation. No Eligible Employee shall be
granted an Option under the Plan which permits his or her rights to purchase
shares of Stock under the Plan, together with other options to purchase shares
of Stock or other stock under all other employee stock purchase plans of the
Company, any Parent Corporation or any Subsidiary Corporation subject to Section
423 of the Code, to accrue at a rate which exceeds $25,000 of fair market value
of such shares of Stock or other stock (determined at the time the Option or
other option is granted) for each calendar year in which the Option is
outstanding at any time. For purpose of the limitation imposed by this
subsection, (i) the right to purchase shares of Stock or other stock under an
Option or other option accrues when the Option or other option (or any portion
thereof) first becomes exercisable during the calendar year, (ii) the right to
purchase shares of

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(1) Adjusted from 500,000 to 1,000,000 to reflect the two-for-one stock split
implemented as a 100% stock dividend, effective September 2003.

(2) Adjusted from 100,000 to 200,000 to reflect the two-for-one stock split
implemented as a 100% stock dividend, effective September 2003.

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Stock or other stock under an Option or other option accrues at the rate
provided in the Option or other option, but in no case may such rate exceed
$25,000 of the fair market value of such Stock or other stock (determined at the
time such Option or other option is granted) for any one calendar year, and
(iii) a right to purchase Stock or other stock which has accrued under an Option
or other option may not be carried over to any Option or other option. This
limitation shall be applied in accordance with Section 423(b)(8) of the Code and
the Treasury Regulations thereunder.

                  (d)      Leaves of Absence. During a leave of absence meeting
the requirements of Treasury Regulation Section 1.421-7(h)(2), an Employee may
continue to participate in the Plan by making cash payments to the Company on
each Payday equal to the amount of the Employee's payroll deduction under the
Plan for the Payday immediately preceding the first day of such Employee's leave
of absence.

         4.       EXERCISE OF OPTIONS; OPTION PRICE.

                  (a)      Option Exercise. Each Employee automatically and
without any act on such Employee's part shall be deemed to have exercised such
Employee's Option on the Date of Exercise to the extent that the balance then in
the Employee's Account is sufficient to purchase, at the Option Price, shares of
the Stock subject to the Option. No fractional shares may be purchased upon
exercise of the Option. The balance of the amount credited to the Account of
each Employee that has not been applied to the purchase of shares of Stock on
the Date of Exercise as a result of the prohibition on the purchase of
fractional shares under the Plan shall remain in such Account and shall be
applied to subsequent Option exercises, subject to the terms of Sections 4(d)
and 5(a). If any additional amount remains credited to the Account of an
Employee following the exercise of the Option, the Company or Subsidiary
Corporation employing the Employee shall immediately pay to the Employee the
amount credited to the Employee's Account in one lump sum payment in cash,
without any interest thereon.

                  (b)      Option Price Defined. The option price per share of
Stock (the "Option Price") to be paid by an Employee upon the exercise of the
Employee's Option shall be equal to 85% of the lesser of: (i) the Fair Market
Value of a share of Stock on the Date of Exercise and (ii) the Fair Market Value
of a share of Stock on the Date of Grant. The "Fair Market Value" of a share of
Stock as of a given date shall be (a) the closing price of a share of Stock on
the principal stock exchange or the Nasdaq National Market or Nasdaq SmallCap
Market on which shares of Stock are then outstanding, if any (or as reported on
any composite index which includes such principal stock exchange or Nasdaq
Market), on the trading day previous to such date, or if shares were not traded
on the trading day previous to such date, then on the immediately preceding date
on which a trade occurred, (b) if Stock is not traded on an exchange or Nasdaq
but is quoted on a quotation system other than Nasdaq, the mean between the
closing representative bid and asked prices for the Stock on the trading day
previous to such date as reported by such quotation system, or (c) if Stock is
not publicly traded on an exchange or Nasdaq and not quoted on a quotation
system other than Nasdaq, the Fair Market Value of a share of Stock as
established by the Committee acting in good faith.

                  (c)      Book Entry/Share Certificates. As soon as reasonably
practicable after the purchase of whole shares of Stock upon the exercise of an
Option by an Employee, the Company shall issue the shares of Stock to such
Employee and such shares shall be held in the custody of the Agent for the
benefit of the Employee. The Company or the Agent shall make an entry on its
books and records indicating that the shares of Stock purchased in connection
with such exercise have been duly issued as of that date to such Employee. An
Employee shall have the right at any time to request in writing a certificate or
certificates for all or a portion of the whole shares of Stock purchased
hereunder. Upon receipt of an Employee's written request for any such
certificate, the Company shall (or shall cause the Agent to), within ten (10)
days or, if later, as soon as reasonably practicable after the date of such
receipt, deliver any such certificate to the Employee. Nothing in this
subsection (c) shall prohibit the sale or other disposition by an Employee of
shares of Stock purchased hereunder. In the event the Company is required to
obtain authority from any commission or agency to issue any certificate or
certificates for all or a portion of the whole shares of Stock purchased
hereunder, the Company shall seek to obtain such authority as soon as reasonably
practicable.

                  (d)      Pro Rata Allocations. If the total number of shares
of Stock for which Options are to be exercised on any date exceeds the number of
shares of Stock remaining unsold under the Plan (after deduction for all shares
of Stock for which Options have theretofore been exercised), the Committee shall

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make a pro rata allocation of the available remaining shares of Stock in as
nearly a uniform manner as shall be practicable and the balance of the amount
credited to the Account of each Employee which has not been applied to the
purchase of shares of Stock shall be paid to such Employee in one lump sum in
cash within thirty (30) days after the Date of Exercise, without any interest
thereon.

                  (e)      Information Statement. The Company shall provide each
Employee whose Option is exercised with an information statement in accordance
with Section 6039(a) of the Code and the Treasury Regulations thereunder. The
Company shall maintain a procedure for identifying certificates of shares of
Stock sold upon the exercise of Options in accordance with Section 6039(b) of
the Code.

         5.       WITHDRAWAL FROM THE PLAN.

                  (a)      Withdrawal Election. An Employee may withdraw from
participation under the Plan at any time, except that an Employee may not
withdraw during the last ten (10) days of any Option Period. An Employee
electing to withdraw from the Plan must deliver to the Company a notice of
withdrawal in a form prepared by the Committee (the "Withdrawal Election") not
later than ten (10) days prior to the Date of Exercise for such Option Period.
Upon receipt of an Employee's Withdrawal Election, the Company or Subsidiary
Corporation employing the Employee shall pay to the Employee the amount credited
to the Employee's Account in one lump sum payment in cash, without any interest
thereon, and subject to Section 4(c), at the Employee's request the Company
shall (or shall cause the Agent to) deliver to the Employee certificates for any
whole shares of Stock previously purchased by the Employee (the value of any
fractional share to be returned to such Employee by check), in either case
within thirty (30) days of receipt of the Employee's Withdrawal Election. Upon
receipt of an Employee's Withdrawal Election by the Company, the Employee shall
cease to participate in the Plan and the Employee's Option for such Option
Period shall terminate.

                  (b)      Eligibility following Withdrawal. An Employee who
withdraws from the Plan with respect to an Option Period, and who is still an
Eligible Employee, may elect to participate again in the Plan for any subsequent
Offering Period by delivering to the Company an Authorization not later than ten
(10) days before the first day of the Offering Period pursuant to Section 3(b).

         6.       TERMINATION OF EMPLOYMENT.

                  (a)      Termination of Employment Other than by Death. If the
employment of an Employee with the Company and the Subsidiary Corporation
terminates other than by death, the Employee's participation in the Plan
automatically and without any act on the Employee's part shall terminate as of
the date of the termination of the Employee's employment. As soon as practicable
after such a termination of employment, the Company or Subsidiary Corporation
employing the Employee shall pay to the Employee the amount credited to the
Employee's Account in one lump sum payment in cash, without any interest
thereon, and subject to Section 4(c), at the Employee's request the Company
shall (or shall cause the Agent to) deliver to the Employee certificates for any
whole shares of Stock previously purchased by the Employee (the value of any
fractional share to be returned to such Employee by check). Upon an Employee's
termination of employment covered by this subsection, the Employee's
Authorization and Option under the Plan shall terminate.

                  (b)      Termination by Death. If the employment of an
Employee is terminated by the Employee's death, the executor of the Employee's
will or the administrator of the Employee's estate, by written notice to the
Company, may request payment of the balance in the Employee's Account, in which
event the Company or Subsidiary Corporation employing the Employee shall pay the
amount credited to the Employee's Account in one lump sum payment in cash,
without any interest thereon, and subject to Section 4(c), at the Employee's
request the Company shall (or shall cause the Agent to) deliver to the Employee
certificates for any whole shares of Stock previously purchased by the Employee
(the value of any fractional share to be returned to such Employee by check) as
soon as practicable after receiving such notice. Upon receipt of such notice,
the Employee's Authorization and Option under the Plan shall terminate. If the
Company does not receive such notice prior to the next Date of Exercise, the
Employee's Option shall be deemed to have been exercised on such Date of
Exercise.

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         7.       RESTRICTION UPON ASSIGNMENT. An Option granted under the Plan
shall not be transferable other than by will or the laws of descent and
distribution, and is exercisable during the Employee's lifetime only by the
Employee. Except as provided in Section 6(b) hereof, an Option may not be
exercised to any extent except by the Employee. The Company shall not recognize
and shall be under no duty to recognize any assignment or alienation of the
Employee's interest in the Plan, the Employee's Option or any rights under the
Employee's Option.

         8.       NO RIGHTS OF STOCKHOLDERS UNTIL SHARES ISSUED. With respect to
shares of Stock subject to an Option, an Employee shall not be deemed to be a
stockholder of the Company, and the Employee shall not have any of the rights or
privileges of a stockholder, until such shares have been issued to the Employee
or his or her nominee following exercise of the Employee's Option. No
adjustments shall be made for dividends (ordinary or extraordinary, whether in
cash securities, or other property) or distribution or other rights for which
the record date occurs prior to the date of such issuance, except as otherwise
expressly provided herein.

         9.       CHANGES IN THE STOCK AND CORPORATE EVENTS; ADJUSTMENT OF
OPTIONS.

                  (a)      Subject to Section 9(c), in the event that the
Committee, in its sole discretion, determines that any dividend or other
distribution (whether in the form of cash, 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 Stock or other securities of the Company, issuance of warrants or
other rights to purchase Stock or other securities of the Company, or other
similar corporate transaction or event, affects the Stock such that an
adjustment 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 an Option, then the Committee shall, in such manner as it may
deem equitable, adjust any or all of:

                           (i)      the number and kind of shares of Stock (or
         other securities or property) with respect to which Options may be
         granted (including, but not limited to, adjustments of the limitation
         in Section 3(a) on the maximum number of shares of Stock which may be
         purchased),

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

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

                  (b)      Subject to Section 9(c), in the event of any
transaction or event described in Section 9(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 Committee, in its
sole 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 and either automatically or upon the Employee's
request, is hereby authorized to take any one or more of the following actions
whenever the Committee 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 that all Options outstanding
         shall terminate without being exercised on such date as the Committee
         determines in its sole discretion;

                           (ii)     To provide that all Options outstanding
         shall be exercised prior to the Date of Exercise of such Options on
         such date as the Committee determines in its sole discretion and such
         Options shall terminate immediately after such exercises.

                           (iii)    To provide for either the purchase of any
         Option outstanding for an amount of cash equal to the amount that could
         have been obtained upon the exercise of such Option

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         had such Option been currently exercisable, or the replacement of such
         Option with other rights or property selected by the Committee in its
         sole discretion;

                           (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, 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; and

                           (v)      To make adjustments in the number and type
         of shares of Stock (or other securities or property) subject to
         outstanding Options, or in the terms and conditions of outstanding
         Options, or Options which may be granted in the future.

                  (c)      No adjustment or action described in this Section 9
or in any other provision of the Plan shall be authorized to the extent that
such adjustment or action would cause the Plan to fail to satisfy the
requirements of Section 423 of the Code. Furthermore, no such adjustment or
action shall be authorized to the extent such adjustment or action would result
in short-swing profits liability under Section 16 of the Securities and Exchange
Act of 1934, as amended, or violate the exemptive conditions of Rule 16b-3
unless the Committee determines that the Option is not to comply with such
exemptive conditions. The number of shares of Stock subject to any Option shall
always be rounded to the next whole number.

                  (d)      The existence of the Plan 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 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 Stock or the rights thereof of which are convertible into or
exchangeable for 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.

         10.      USE OF FUNDS; NO INTEREST PAID. All funds received or held by
the Company under the Plan shall be included in the general funds of the Company
free of any trust or other restriction and may be used for any corporate
purpose. No interest will be paid to any Employee or credited to any Employee's
Account with respect to such funds.

         11.      DIVIDENDS.

                  (a)      Cash dividends and other cash distributions received
by the Agent with respect to Stock held in its custody hereunder will be
credited to each Employee's Account in accordance with such Employee's interests
in such Stock, and shall be applied, as soon as practicable after the receipt
thereof by the Agent, to the purchase in the open market at prevailing market
prices of the number of whole shares of Stock that may be purchased with such
funds (after deductions of any bank service fees, brokerage charges, transfer
taxes, and any other transaction fee, expense or cost payable in connection with
the purchase of such shares of Stock and not otherwise paid by the Employer.)

                  (b)      All purchases of shares of Stock made pursuant to
this Section 11 will be made in the name of the Agent or its nominee, and shall
be transferred and credited to the Account(s) of the Employees to which such
dividends or other distributions were credited. Dividends paid in the form of
shares of Stock will be allocated by the Agent, as and when received, with
respect to Stock held in its custody hereunder to the Account of each Employee
in accordance with such Employee's interests in such Stock. Property, other than
Stock or cash, received by the Agent as a distribution on Stock held in its
custody hereunder, shall be sold by the Agent for the accounts of Employees, and
the Agent shall treat the proceeds of such sale in the same manner as cash
dividends received by the Agent on Stock held in its custody hereunder.

         12.      AMENDMENT, SUSPENSION OR TERMINATION OF THE PLAN. Each of the
Board and the Committee may amend, suspend, or terminate the Plan at any time
and from time to time, including with

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respect to the duration or frequency of Offering Periods under the Plan,
provided that approval by a vote of the holders of the outstanding shares of the
Company's capital stock entitled to vote shall be required to amend the Plan to:
(a) change the number of shares of Stock that may be sold pursuant to Options
under the Plan, (b) alter the requirements for eligibility to participate in the
Plan, or (c) in any manner that would cause the Plan to no longer be an
"employee stock purchase plan" within the meaning of Section 423(b) of the Code.

         13.      ADMINISTRATION BY COMMITTEE; RULES AND REGULATIONS.

                  (a)      Appointment of Committee. The Committee shall consist
of two or more members, and may be comprised of members of the Board or
Employees. Appointment of Committee members shall be made by the Board and 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.

                  (b)      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 terms of the Options, and to adopt such rules for the administration,
interpretation and application of the Plan as are consistent therewith and to
interpret, amend or revoke any such rules. In its absolute discretion, the Board
may at any time and from time to time exercise any and all rights and duties of
the Committee under the Plan.

                  (c)      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.

                  (d)      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 that 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 Option 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 to the maximum extent
permitted under applicable law and the charter documents of the Company in
respect of any such action, determination or interpretation.

         14.      DESIGNATION OF SUBSIDIARY CORPORATIONS. The Board shall
designate from among the Subsidiary Corporations, as determined from time to
time, the Subsidiary Corporation or Subsidiary Corporations whose Employees
shall be eligible to be granted Options under the Plan. The Board may designate
a Subsidiary Corporation, or terminate the designation of a Subsidiary
Corporation, without the approval of the stockholders of the Company.

         15.      NO RIGHTS AS AN EMPLOYEE. Nothing in the Plan shall be
construed to give any person (including any Eligible Employee) the right to
remain in the employ of the Company, a Parent Corporation or a Subsidiary
Corporation or to affect the right of the Company, any Parent Corporation or any
Subsidiary Corporation to terminate the employment of any person (including any
Eligible Employee) at any time, with or without cause.

         16.      TERM; APPROVAL BY STOCKHOLDERS. Subject to approval by the
stockholders of the Company in accordance with this Section, the Plan shall
remain in effect until terminated in accordance with Section 12. No Option may
be granted during any period of suspension of the Plan or after termination of
the Plan. The Plan shall be submitted for the approval of the Company's
stockholders within twelve (12) months after the date of the adoption of the
Plan by the Board. Options may be granted prior to such stockholder approval;
provided, however, that such Options shall not be exercisable

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prior to the time when the Plan is approved by the Company's stockholders; and,
provided, further, that if such approval has not been obtained by the end of
said 12-month period, all Options previously granted under the Plan shall
thereupon terminate without being exercised.

         17.      EFFECT UPON OTHER PLANS. The adoption of the Plan shall not
affect any other compensation or incentive plans in effect for the Company, any
Parent Corporation or any Subsidiary Corporation. Nothing in this Plan shall be
construed to limit the right of the Company, any Parent Corporation or any
Subsidiary Corporation to: (a) establish any other forms of incentives or
compensation for employees of the Company, any Parent Corporation or any
Subsidiary Corporation, or (b) grant or assume options 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, firm or association.

         18.      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 Options prior to fulfillment of
all the following conditions:

                  (a)      The admission of such shares to listing on all stock
exchanges, if any, on which 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 Committee 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 Committee shall, in its
absolute discretion, determine to be necessary or advisable;

                  (d)      The payment to the Company of all amounts which it is
required to withhold under federal, state or local law upon exercise of the
Option; and

                  (e)      The lapse of such reasonable period of time following
the exercise of the Option as the Committee may from time to time establish for
reasons of administrative convenience.

         19.      NOTIFICATION OF DISPOSITION. Each Employee shall give prompt
notice to the Company of any disposition or other transfer of any shares of
Stock purchased upon exercise of an Option if such disposition or transfer is
made: (a) within two (2) years from the Date of Grant of the Option, or (b)
within one (1) year after the transfer of such shares of Stock to such Employee
upon exercise of such Option. Such notice shall specify the date of such
disposition or other transfer and the amount realized, in cash, other property,
assumption of indebtedness or other consideration, by the Employee in such
disposition or other transfer.

         20.      NOTICES. Any notice to be given under the terms of the Plan to
the Company shall be addressed to the Company in care of its Secretary and any
notice to be given to any Employee shall be addressed to such Employee at such
Employee's last address as reflected in the Company's records. By a notice given
pursuant to this Section, either party may designate a different address for
notices to be given to it, him or her. Any notice which is required to be given
to an Employee shall, if the Employee is then deceased, be given to the
Employee's personal representative if such representative has previously
informed the Company of his status and address by written notice under this
Section. Any notice shall have been deemed duly given if enclosed in a properly
sealed envelope or wrapper addressed as aforesaid at the time it is deposited
(with postage prepaid) in a post office or branch post office regularly
maintained by the United States Postal Service.

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

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<PAGE>

                  I hereby certify that the Gen-Probe Incorporated Employee
Stock Purchase Plan was adopted by the Board of Directors of Gen-Probe
Incorporated on March 3, 2003 and by the Compensation Committee of the Board of
Directors on April 2, 2003.

                  Executed on this 2nd day of April, 2003.

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

                                  * * * * * * *

                  I hereby certify that the Gen-Probe Incorporated Employee
Stock Purchase Plan was approved by the stockholders of Gen-Probe Incorporated
on May 29, 2003.

                  Executed on this 29th day of May, 2003.

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

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