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                           CIPHERGEN BIOSYSTEMS, INC.

                             1993 STOCK OPTION PLAN

                  (As Amended and Restated on October 27, 1994)
                    (As Amended and Restated on May 10, 1995)
                 (As Amended and Restated on September 5, 1996)
                   (As Amended and Restated on July 31, 1997)
                   (As Amended and Restated on July 28, 1998)
                  (As Amended and restated on September 9,1999)


1.       PURPOSES.

         (a) The purpose of the Plan is to provide a means by which selected
Employees and Directors of and Consultants to the Company and its Affiliates,
may be given an opportunity to purchase stock of the Company.

         (b) The Company, by means of the Plan, seeks to retain the services
of persons who are now Employees or Directors of or Consultants to the
Company, to secure and retain the services of new Employees, Directors and
Consultants, and to provide incentives for such persons to exert maximum
efforts for the success of the Company and its Affiliates.

         (c) The Company intends that the Options issued under the Plan
shall, in the discretion of the Board or any Committee to which
responsibility for administration of the Plan has been delegated pursuant to
subsection 3(c), be either Incentive Stock Options or Nonstatutory Stock
Options. All Options shall be separately designated Incentive Stock Options
or Nonstatutory Stock Options at the time of grant, and in such form as
issued pursuant to Section 6, and a separate certificate or certificates will
be issued for shares purchased on exercise of each type of Option.

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2.       DEFINITIONS.

         (a) "AFFILIATE" means any parent corporation or subsidiary
corporation, whether now or hereafter existing, as those terms are defined in
Sections 424(e) and (f) respectively, of the Code.

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

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

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

         (e) "COMPANY" means Ciphergen Biosystems, Inc., a California
corporation.

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

         (g) "CONTINUOUS STATUS AS AN EMPLOYEE, DIRECTOR OR CONSULTANT" means
the employment or relationship as a Director or Consultant is not interrupted
or terminated by the Company or any Affiliate. The Board, in its sole
discretion, may determine whether Continuous Status as an Employee, Director
or Consultant shall be considered interrupted in the case of: (i) any leave
of absence approved by the Board, including sick leave, military leave, or
any other personal leave; or (ii) transfers between locations of the Company
or between the Company, Affiliates or their successors.

         (h)      "DIRECTOR" means a member of the Board.

         (i) "DISINTERESTED PERSON" means a Director: (i) who was not during
the one year prior to service as an administrator of the Plan granted or
awarded equity securities pursuant to the Plan or any other plan of the
Company or any of its affiliates entitling the participants therein to
acquire

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equity securities of the Company or any of its affiliates except as permitted
by Rule 16b-3(c)(2)(i); or (ii) who is otherwise considered to be a
"disinterested person" in accordance with Rule 16b-3(c)(2)(i), or any other
applicable rules, regulations or interpretations of the Securities and
Exchange Commission.

         (j) "EMPLOYEE" means any person, including Officers and Directors,
employed by the Company or any Affiliate of the Company. Neither service as a
Director nor payment of a director's fee by the Company shall be sufficient
to constitute "employment" by the Company.

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

         (l) "FAIR MARKET VALUE" means, as of any date, the value of the
common stock of the Company determined by the Board pursuant to Rule
260.140.50 of Title 10 of the California Code of Regulations.

         (m) "INCENTIVE STOCK OPTION" means an Option intended to qualify as
an incentive stock option within the meaning of Section 422 of the Code and
the regulations promulgated thereunder.

         (n) "NONSTATUTORY STOCK OPTION" means an Option not intended to
qualify as an Incentive Stock Option.

         (o) "OFFICER" means a person who is an officer of the Company within
the meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

         (p) "OPTION" means a stock option granted pursuant to the Plan.

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

         (r) "OPTIONED STOCK" means the common stock of the Company subject
to an Option.

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

         (t) "PLAN" means this 1993 Stock Option Plan.

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

3.       ADMINISTRATION.

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

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

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

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

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

         (c) The Board may delegate administration of the Plan to a committee
composed of not fewer than two (2) members (the "Committee"), all of the
members of which Committee shall be

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Disinterested Persons, if required under subsection 3(d). If administration
is delegated to a Committee, the Committee shall have, in connection with the
administration of the Plan, the powers theretofore possessed by the Board
(and references in this Plan to the Board shall thereafter be to the
Committee), subject, however, to such resolutions, not inconsistent with the
provisions of the Plan, as may be adopted from time to time by the Board. The
Board may abolish the Committee at any time and revest in the Board the
administration of the Plan. Additionally, prior to the date of the first
registration of an equity security of the Company under Section 12 of the
Exchange Act, and notwithstanding anything to the contrary contained herein,
the Board may delegate administration of the Plan to any person or persons
and the term "Committee" shall apply to any person or persons to whom such
authority has been delegated.

         (d) Any requirement that an administrator of the Plan be a
Disinterested Person shall not apply (i) prior to the date of the first
registration of an equity security of the Company under Section 12 of the
Exchange Act, or (ii) if the Board or the Committee expressly declares that
such requirement shall not apply. Any Disinterested Person shall otherwise
comply with the requirements of Rule 16b-3.

4.       SHARES SUBJECT TO THE PLAN.

         (a) Subject to the provisions of Section 10 relating to adjustments
upon changes in stock, the stock that may be sold pursuant to Options shall
not exceed in the aggregate five million eight hundred twenty five thousand
(5,825,000) shares of the Company's common stock. If any Option shall for any
reason expire or otherwise terminate without having been exercised in full,
the stock not purchased under such Option shall revert to and again become
available for issuance under the Plan.

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

5.       ELIGIBILITY.

         (a) Incentive Stock Options may be granted only to Employees.
Nonstatutory Stock Options may be granted only to Employees, Directors or
Consultants.

         (b) A Director shall in no event be eligible for the benefits of the
Plan unless at the time discretion is exercised in the selection of the
Director as a person to whom Options may be granted, or in the determination
of the number of shares which may be covered by Options granted to the
Director: (i) the Board has delegated its discretionary authority over the
Plan to a Committee which consists solely of Disinterested Persons; or (ii)
the Plan otherwise complies with the requirements of Rule 16b-3. The Board
shall otherwise comply with the requirements of Rule 16b-3. This subsection
5(b) shall not apply (i) prior to the date of the first registration of an
equity security of the Company under Section 12 of the Exchange Act, or (ii)
if the Board or Committee expressly declares that it shall not apply.

         (c) No person shall be eligible for the grant of an Option if, at
the time of grant, such person owns (or is deemed to own pursuant to Section
424(d) of the Code) stock possessing more than ten percent (10%) of the total
combined voting power of all classes of stock of the Company or of any of its
Affiliates unless the exercise price of such Option is at least one hundred
ten percent (110%) of the Fair Market Value of such stock at the date of
grant and the Option is not exercisable after the expiration of five (5)
years from the date of grant.

6.       OPTION PROVISIONS.

         Each Option shall be in such form and shall contain such terms and
conditions as the Board shall deem appropriate. The provisions of separate
Options need not be identical, but each Option

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shall include (through incorporation of provisions hereof by reference in the
Option or otherwise) the substance of each of the following provisions:

         (a) TERM. No Option shall be exercisable after the expiration of ten
(10) years from the date it was granted.

         (b) PRICE. The exercise price of each Incentive Stock Option shall
be not less than one hundred percent (100%) of the Fair Market Value of the
stock subject to the Option on the date the Option is granted. The exercise
price of each Nonstatutory Stock Option shall be not less than eighty-five
percent (85%) of the Fair Market Value of the stock subject to the Option on
the date the Option is granted.

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

         In the case of any deferred payment arrangement, interest shall be
payable at least annually and shall be charged at the minimum rate of
interest necessary to avoid the treatment as interest, under any applicable
provisions of the Code, of any amounts other than amounts stated to be
interest under the deferred payment arrangement.

         (d) TRANSFERABILITY. An Incentive Stock Option shall not be
transferable except by will or by the laws of descent and distribution, and
shall be exercisable during the lifetime of the person

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to whom the Option is granted only by such person. A Nonstatutory Stock
Option shall not be transferable except by will or by the laws of descent and
distribution or pursuant to a qualified domestic relations order satisfying
the requirements of Rule 16b-3 and the rules thereunder (a "QDRO"), and shall
be exercisable during the lifetime of the person to whom the Option is
granted only by such person or any transferee pursuant to a QDRO. The person
to whom the Option is granted may, by delivering written notice to the
Company, in a form satisfactory to the Company, designate a third party who,
in the event of the death of the Optionee, shall thereafter be entitled to
exercise the Option.

         (e) VESTING. The total number of shares of stock subject to an
Option may, but need not, be allotted in periodic installments (which may,
but need not, be equal). The Option Agreement may provide that from time to
time during each of such installment periods, the Option may become
exercisable ("vest") with respect to some or all of the shares allotted to
that period, and may be exercised with respect to some or all of the shares
allotted to such period and/or any prior period as to which the Option became
vested but was not fully exercised. The vesting provisions of individual
Options may vary but in each case will provide for vesting of at least twenty
percent (20%) of the total number of shares subject to the Option per year.
During the remainder of the term of the Option (if its term extends beyond
the end of the installment periods), the Option may be exercised from time to
time with respect to any shares then remaining subject to the Option. The
provisions of this subsection 6(e) are subject to any Option provisions
governing the minimum number of shares as to which an Option may be exercised.

         (f) SECURITIES LAW COMPLIANCE. The Company may require any Optionee,
or any person to whom an Option is transferred under subsection 6(d), as a
condition of exercising any such Option, (1) to give written assurances
satisfactory to the Company as to the Optionee's knowledge

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and experience in financial and business matters and/or to employ a purchaser
representative reasonably satisfactory to the Company who is knowledgeable
and experienced in financial and business matters, and that he or she is
capable of evaluating, alone or together with the purchaser representative,
the merits and risks of exercising the Option; and (2) to give written
assurances satisfactory to the Company stating that such person is acquiring
the stock subject to the Option for such person's own account and not with
any present intention of selling or otherwise distributing the stock. These
requirements, and any assurances given pursuant to such requirements, shall
be inoperative if (i) the issuance of the shares upon the exercise of the
Option has been registered under a then currently effective registration
statement under the Securities Act of 1933, as amended (the "Securities
Act"), or (ii) as to any particular requirement, a determination is made by
counsel for the Company that such requirement need not be met in the
circumstances under the then applicable securities laws.

         (g) TERMINATION OF EMPLOYMENT OR RELATIONSHIP AS A DIRECTOR OR
CONSULTANT. In the event an Optionee's Continuous Status as an Employee,
Director or Consultant terminates (other than upon the Optionee's death or
disability), the Optionee may exercise his or her Option, (to the extent that
the Optionee was entitled to exercise it at the date of termination) but only
within such period of time ending on the earlier of (i) the date three (3)
months after the termination of the Optionee's Continuous Status as an
Employee, Director or Consultant (or such longer or shorter period, which in
no event shall be less than thirty (30) days, specified in the Option
Agreement), or (ii) the expiration of the term of the Option as set forth in
the Option Agreement. If, after termination, the Optionee does not exercise
his or her Option within the time specified in the Option Agreement, the
Option shall terminate, and the shares covered by such Option shall revert to
and again become available for issuance under the Plan.

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         (h) DISABILITY OF OPTIONEE. In the event an Optionee's Continuous
Status as an Employee, Director or Consultant terminates as a result of the
Optionee's disability, the Optionee may exercise his or her Option (to the
extent that the Optionee was entitled to exercise it at the date of such
termination), but only within such period of time ending on the earlier of
(i) the date twelve (12) months following such termination (or such longer or
shorter period, which in no event shall be less than six (6) months,
specified in the Option Agreement), or (ii) the expiration of the term of the
Option as set forth in the Option Agreement. If, at the date of termination,
the Optionee is not entitled to exercise his or her entire Option, the shares
covered by the unexercisable portion of the Option shall revert to and again
become available for issuance under the Plan. If, after termination, the
Optionee does not exercise his or her Option within the time specified
herein, the Option shall terminate, and the shares covered by such Option
shall revert to and again become available for issuance under the Plan.

         (i) DEATH OF OPTIONEE. In the event of the death of an Optionee
during, or within a period specified in the Option after the termination of,
the Optionee's Continuous Status as an Employee, Director or Consultant, the
Option may be exercised (to the extent the Optionee was entitled to exercise
the Option at the date of death) by the Optionee's estate, by a person who
acquired the right to exercise the Option by bequest or inheritance or by a
person designated to exercise the Option upon the Optionee's death pursuant
to subsection 6(d), but only within the period ending on the earlier of (i)
the date eighteen (18) months following the date of death (or such longer or
shorter period, which in no event shall be less than six (6) months,
specified in the Option Agreement), or (ii) the expiration of the term of
such Option as set forth in the Option Agreement. If, at the time of death,
the Optionee was not entitled to exercise his or her entire Option, the
shares covered by the unexercisable portion of the Option shall revert to and
again become available for

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issuance under the Plan. If, after death, the Option is not exercised within
the time specified herein, the Option shall terminate, and the shares covered
by such Option shall revert to and again become available for issuance under
the Plan.

         (j) EARLY EXERCISE. The Option may, but need not, include a
provision whereby the Optionee may elect at any time while an Employee,
Director or Consultant to exercise the Option as to any part or all of the
shares subject to the Option prior to the full vesting of the Option. Any
unvested shares so purchased shall be subject to a repurchase right in favor
of the Company, with the repurchase price to be equal to the original
purchase price of the stock, or to any other restriction the Board determines
to be appropriate; PROVIDED, HOWEVER, that (i) the right to repurchase at the
original purchase price shall lapse at a minimum rate of twenty percent (20%)
per year over five (5) years from the date the Option was granted, and (ii)
such right shall be exercisable only within (A) the ninety (90) day period
following the termination of employment or the relationship as a Director or
Consultant, or (B) such longer period as may be agreed to by the Company and
the Optionee (for example, for purposes of satisfying the requirements of
Section 1202(c)(3) of the Code (regarding "qualified small business stock")),
and (iii) such right shall be exercisable only for cash or cancellation of
purchase money indebtedness for the shares. Should the right of repurchase be
assigned by the Company, the assignee shall pay the Company cash equal to the
difference between the original purchase price and the stock's Fair Market
Value if the original purchase price is less than the stock's Fair Market
Value.

         (k) WITHHOLDING. To the extent provided by the terms of an Option
Agreement, the Optionee may satisfy any federal, state or local tax
withholding obligation relating to the exercise of such Option by any of the
following means or by a combination of such means: (1) tendering a cash
payment; (2) authorizing the Company to withhold shares from the shares of
the common stock

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otherwise issuable to the participant as a result of the exercise of the
Option; or (3) delivering to the Company owned and unencumbered shares of the
common stock of the Company.

7.       COVENANTS OF THE COMPANY.

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

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

8.       USE OF PROCEEDS FROM STOCK.

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

9.       MISCELLANEOUS.

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

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         (b) Subject to Section 59(b) of the Company's Bylaws, throughout the
term of any Option, the Company shall deliver to the holder of such Option,
not later than one hundred twenty (120) days after the close of each of the
Company's fiscal years during the Option term, such financial and other
information regarding the Company as comprises the annual report to the
stockholders of the Company provided for in the bylaws of the Company.

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

         (d) To the extent that the aggregate Fair Market Value (determined
at the time of grant) of stock with respect to which Incentive Stock Options
granted after 1986 are exercisable for the first time by any Optionee during
any calendar year under all plans of the Company and its Affiliates exceeds
one hundred thousand dollars ($100,000), the Options or portions thereof
which exceed such limit (according to the order in which they were granted)
shall be treated as Nonstatutory Stock Options.

         (e) The Board or the Committee shall have the authority to effect,
at any time and from time to time (i) the repricing of any outstanding
Options under the Plan and/or (ii) with the consent of the affected holders
of Options, the cancellation of any outstanding Options and the grant in
substitution therefor of new Options under the Plan covering the same or
different numbers of shares of Common Stock, but having an exercise price per
share not less than eighty-five percent (85%) of the Fair Market Value (one
hundred percent (100%) of the Fair Market Value in the case of an Incentive
Stock Option or, in the case of a ten percent (10%) stockholder (as defined
in

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subsection 5(c)), not less than one hundred and ten percent (110%) of the
Fair Market Value) per share of Common Stock on the new grant date.

10.      ADJUSTMENTS UPON CHANGES IN STOCK.

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

         (b) In the event of: (1) a merger or consolidation in which the
Company is not the surviving corporation or (2) a reverse merger in which the
Company is the surviving corporation but the shares of the Company's common
stock outstanding immediately preceding the merger are converted by virtue of
the merger into other property, whether in the form of securities, cash or
otherwise then to the extent permitted by applicable law: (i) any surviving
corporation shall assume any Options outstanding under the Plan or shall
substitute similar Options for those outstanding under the Plan, or (ii) such
Options shall continue in full force and effect. In the event any surviving
corporation refuses to assume or continue such Options, or to substitute
similar options for those outstanding under the Plan, then such Options shall
be terminated if not exercised prior to such event. In the event of a
dissolution or liquidation of the Company, any Options outstanding under the
Plan shall terminate if not exercised prior to such event.

11.      AMENDMENT OF THE PLAN AND OPTIONS.

         (a) The Board at any time, and from time to time, may amend the
Plan. However, except as provided in Section 10 relating to adjustments upon
changes in stock, no amendment shall be

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effective unless approved by the stockholders of the Company within twelve
(12) months before or after the adoption of the amendment, where the
amendment will:

                  (1) Increase the number of shares reserved for Options
under the Plan;

                  (2) Modify the requirements as to eligibility for
participation in the Plan (to the extent such modification requires
stockholder approval in order for the Plan to satisfy the requirements of
Section 422 of the Code); or

                  (3) Modify the Plan in any other way if such modification
requires stockholder approval in order for the Plan to satisfy the
requirements of Section 422 of the Code or to comply with the requirements of
Rule 16b-3.

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

         (c) Rights and obligations under any Option granted before amendment
of the Plan shall not be altered by any amendment of the Plan unless (i) the
Company requests the consent of the person to whom the Option was granted and
(ii) such person consents in writing. The Board at any time, and from time to
time, may amend an Option. However, rights and obligations under any Option
granted before the amendment of such Option shall not be impaired by any such
amendment unless (i) the Company requests the consent of the person to whom
the Option was granted and (ii) such person consents in writing.

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12.      TERMINATION OR SUSPENSION OF THE PLAN.

         (a) The Board may suspend or terminate the Plan at any time. Unless
sooner terminated, the Plan shall terminate on December 13, 2003, which shall
be within ten (10) years from the date the Plan is adopted by the Board or
approved by the stockholders of the Company, whichever is earlier. No Options
may be granted under the Plan while the Plan is suspended or after it is
terminated.

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

13.      EFFECTIVE DATE OF PLAN.

         The Plan shall become effective as determined by the Board, but no
Options granted under the Plan shall be exercised unless and until the Plan
has been approved by the stockholders of the Company, and, if required, an
appropriate permit has been issued by the Commissioner of Corporations of the
State of California.















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