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                                                                    EXHIBIT 10.4


                                     CEPHEID

                        2000 EMPLOYEE STOCK PURCHASE PLAN


     1.   Purpose. This Plan is intended to provide Employees of the Company and
its Designated Subsidiaries an opportunity to purchase Common Stock through
accumulated payroll deductions.

     2.   Definitions.

          (a)  "Administrator" means the Board or the persons appointed by the
Board to administer this Plan pursuant to Section 13.

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

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

          (d)  "Common Stock" means the Common Stock of the Company.

          (e)  "Company" means Cepheid, a California corporation.

          (f)  "Compensation" means all regular, straight-time gross earnings of
a Participant, including commissions but exclusive of payments for overtime,
shift premium, incentive compensation, incentive payments, bonuses and other
compensation.

          (g)  "Continuous Employment" means the absence of any interruption or
termination of service as an Employee. Continuous Employment shall not be
considered interrupted in the case of a leave of absence agreed to in writing by
the Company, provided that either (i) the leave does not exceed 90 days or (ii)
re-employment upon expiration of the leave is guaranteed by contract or statute.

          (h)  "Designated Subsidiaries" means the Subsidiaries that have been
designated by the Board from time to time in its sole discretion to participate
in this Plan.

          (i)  "Employee" means any person, including an officer, who is
employed for at least 20 hours per week by the Company or one of its Designated
Subsidiaries during at least 22 weeks in any calendar year. Whether an
individual qualifies as an Employee shall be determined by the Administrator, in
its sole discretion, by reference to Section 3401(c) of the Code and the
regulations promulgated thereunder; unless the Administrator makes a contrary
determination, the Employees of the Company shall, for all purposes of this
Plan, be those individuals who satisfy the customary employment criteria set
forth above and are carried as employees by the Company or a Designated
Subsidiary for regular payroll purposes.

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          (j)  "Purchase Date" means such business days during each Offering
Period of this Plan as may be identified by the Administrator pursuant to
Section 8.

          (k)  "Interim Offering Date" means the first business day following a
Purchase Date other than the last Purchase Date of an Offering Period.

          (l)  "Offering Date" means the first business day of an Offering
Period.

          (m)  "Offering Period" means a period established by the Administrator
pursuant to Section 4 during which payroll deductions are accumulated from one
or more Participants and applied to the purchase of Common Stock.

          (n)  "Participant" means an Employee who has elected to participate in
this Plan pursuant to Section 5.

          (o)  "Plan" means this Cepheid 2000 Employee Stock Purchase Plan.

          (p)  "Purchase Right" means a right to purchase Common Stock granted
               pursuant to Section 7.

          (q)  "Subsidiary" means, from time to time, any corporation, domestic
or foreign, of which not less than 50% of the voting shares are held by the
Company or another Subsidiary of the Company.

     3.   Eligibility.

          (a)  Regular Participation. Any person who is, or will be, an Employee
on an Offering Date shall be eligible to participate in this Plan during the
corresponding Offering Period, subject to the requirements of Section 5(a).

          (b)  Interim Participation. Any person who becomes an Employee after
an Offering Date shall be eligible to participate in this Plan during the
corresponding Offering Period, but only on and beginning with the first Interim
Offering Date.

          (c)  No Participation by Five-Percent Stockholders. Notwithstanding
paragraphs (a) and (b) of this Section 3, an Employee shall not participate in
this Plan during an Offering Period if immediately after the grant of a Purchase
Right on the Offering Date or Interim Offering Date, the Employee (or any other
person whose stock would be attributed to the Employee under Section 424(d) of
the Code) would own stock possessing five percent or more of the total combined
voting power or value of all classes of stock of the Company or of any
Subsidiary. For this purpose, an Employee is treated as owning stock that he or
she could purchase by exercise of Purchase Rights or other options.


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     4.   Offering Periods.

          Unless otherwise determined by the Administrator:

          (a)  the first Offering Period under this Plan shall begin on the
first business day before the effective date of a firmly underwritten initial
public offering of Common Stock and shall end on the last business day of June
2002;

          (b)  the duration of each Offering Period (other than the first
Offering Period) shall be 24 months (measured from the first business day of the
first month to the last business day of the 12th month);

          (c)  a new Offering Period shall begin on the first business day after
the last Purchase Date of an Offering Period; and

          (d)  an Offering Period shall terminate on the first date that no
Participants are enrolled in it.

     5.   Participation.

          (a)  An Employee may become a Participant in this Plan by completing a
subscription agreement, in such form or forms as the Administrator may approve
from time to time, and delivering it to the Administrator within 15 days before
the applicable Offering Date or Interim Offering Date, unless another time for
filing the subscription agreement is set by the Administrator for all Employees
with respect to a given Offering Period. The subscription agreement shall
authorize payroll deductions pursuant to this Plan and shall have such other
terms as the Administrator may specify from time to time.

          (b)  At the end of an Offering Period, each Participant in the
Offering Period who remains an Employee shall be automatically enrolled in the
next succeeding Offering Period (a "Re-enrollment") unless, in a manner and at a
time specified by the Administrator, but in no event later than the day before
the Offering Date of such succeeding Offering Period, the Participant notifies
the Administrator in writing that the Participant does not wish to be
re-enrolled. Re-enrollment shall be at the withholding percentage specified in
the Participant's most recent subscription agreement unless the Participant
changes that percentage by timely written notice. No Participant shall be
automatically re-enrolled whose participation has terminated by operation of
Section 10.

     6.   Payroll Deductions.

          (a)  Each Participant shall have withheld a percentage of his or her
Compensation received during an Offering Period. Withholding shall be in whole
percentages of such Compensation, up to a maximum (not to exceed 15%)
established by the Administrator from time to time, as specified by the
Participant in his or her subscription agreement. Payroll deductions for a
Participant during an Offering Period shall begin with the first payroll
following


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the Offering Date or Interim Offering Date and shall end on the last Purchase
Date of the Offering Period, unless sooner terminated by the Participant as
provided in Section 10.

          (b)  All payroll deductions made by a Participant shall be credited to
the Participant's account under this Plan. A Participant may not make any
additional payments into such account.

          (c)  A Participant may reduce the rate of his or her payroll
deductions to 0% at any time during an Offering Period, effective 15 days after
the Participant files with the Administrator a new subscription agreement
authorizing the change. A Participant may make other changes to the rate of his
or her payroll deductions during an Offering Period effective the day after the
first Purchase Date that is at least 15 days after the Administrator's receipt
of a new subscription agreement authorizing the change.

     7.   Purchase Rights.

          (a)  Grant of Purchase Rights. On the Offering Date, or (if
applicable) Interim Offering Date of each Offering Period, the Participant shall
be granted a Purchase Right to purchase during the Offering Period the number of
shares of Common Stock determined by dividing (i) $25,000 multiplied by the
number of (whole or part) calendar years in the Offering Period by (ii) the fair
market value of a share of Common Stock on the Offering Date or Interim Offering
Date.

          (b)  Terms of Purchase Rights. Except as otherwise determined by the
Administrator, each Purchase Right shall have the following terms:

               (i)   The per-share price of the shares subject to a Purchase
                     Right shall be 85% of the lower of the fair market values
                     of a share of Common Stock on (a) the Offering Date, or
                     Interim Offering Date, on which the Purchase Right was
                     granted and (b) the Purchase Date. The fair market value of
                     the Common Stock on a given date shall be the closing price
                     as reported in the Wall Street Journal; provided, however,
                     that if there is no public trading of the Common Stock on
                     that date, then fair market value shall be determined by
                     the Administrator in its discretion.

               (ii)  Payment for shares purchased by exercise of Purchase Rights
                     shall be made only through payroll deductions under Section
                     6.

               (iii) Upon purchase or disposition of shares acquired by exercise
                     of a Purchase Right, the Participant shall pay, or make
                     provision adequate to the Administrator for payment of, all
                     tax (and similar) withholdings that the Administrator
                     determines, in its discretion, are required due to the
                     acquisition or disposition, including without limitation
                     any such withholding that the Administrator determines in
                     its discretion is necessary to allow the Company and its


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                     Subsidiaries to claim tax deductions or other benefits in
                     connection with the acquisition or disposition.

               (iv)  During his or her lifetime, a Participant's Purchase Right
                     is exercisable only by the Participant.

               (v)   The Purchase Rights will in all respects be subject to the
                     terms and conditions of this Plan, as interpreted by the
                     Administrator from time to time.

     8.   Purchase Dates; Purchase of Shares; Refund of Excess Cash.

          (a)  The Administrator shall establish one or more Purchase Dates for
each Offering Period. Unless otherwise determined by the Administrator,

               (i)   the last business days of December 2000, June 2001,
                     December 2001 and June 2002 shall be the Purchase Dates of
                     the initial Offering Period under this Plan, and

               (ii)  the last trading day of each December and June during a
                     subsequent Offering Period shall be a Purchase Date.

          (b)  Each Participant's Purchase Right shall be exercised
automatically on each Purchase Date during the Offering Period, to purchase the
maximum number of full shares at the applicable price using the Participant's
accumulated payroll deductions.

          (c)  The shares purchased upon exercise of a Purchase Right shall be
deemed to be transferred to the Participant on the Purchase Date.

          (d)  Any cash remaining in a Participant's payroll deduction account
after the purchase of shares on a Purchase Date shall be carried forward in that
account for application on the next Purchase Date; provided that upon
termination of an Offering Period, any such cash shall be promptly refunded to
the Participant.

     9.   Registration and Delivery of Share Certificates.

          (a)  Shares purchased by a Participant under this Plan will be
registered in the name of the Participant, or in the name of the Participant and
his or her spouse, or in the name of the Participant and joint tenant(s) (with
right of survivorship), as designated by the Participant.

          (b)  As soon as administratively feasible after each Purchase Date,
the Company shall deliver to the Participant a certificate representing the
shares purchased upon exercise of a Purchase Right. If approved by the
Administrator in its discretion, the Company may instead (i) deliver a
certificate (or equivalent) to a broker for crediting to the Participant's
account or (ii) make a notation in the Participant's favor of non-certificated
shares on the Company's stock records.


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     10.  Withdrawal; Termination of Employment.

          (a)  A Participant may withdraw all, but not less than all, the
payroll deductions credited to his account under this Plan at any time before a
Purchase Date by giving written notice to the Administrator in a form the
Administrator prescribes from time to time. The Participant's Purchase Right
will automatically terminate on the date of receipt of the notice, all payroll
deductions credited to the Participant's account will be refunded promptly
thereafter, and no further payroll deductions will be made during the Offering
Period.

          (b)  Upon termination of a Participant's Continuous Employment for any
reason, including retirement or death, the payroll deductions credited to the
Participant's account will be promptly refunded to the Participant or, in the
case of death, to the person or persons entitled thereto under Section 14 of
this Plan, and the Participant's Purchase Right will automatically terminate.

          (c)  A Participant's withdrawal from an offering will not affect the
Participant's eligibility to participate in a succeeding offering or in any
similar plan that may be adopted by the Company.

     11.  Use of Funds; No Interest.

          Amounts withheld from Participants' Compensation under this Plan shall
constitute general funds of the Company, may be used for any corporate purpose,
and need not be segregated from other funds. No interest shall accrue on a
Participant's payroll deductions.

     12.  Number of Shares Reserved.

          (a)  The following number of shares of Common Stock are reserved for
issuance under this Plan, and such number may be issued at any time before
termination of this Plan:

               (i)   Beginning the date of approval of this Plan by the
                     stockholders of the Company, 200,000 shares of Common
                     Stock; and

               (ii)  Beginning the first business day of each calendar year
                     starting January 1, 2001, the lesser of an additional (i)
                     200,000 shares of Common Stock, (ii) 0.75% of the
                     outstanding shares of capital stock on such date or (iii)
                     an amount determined by the Board.

          (b)  If the total number of shares that would otherwise be subject to
Purchase Rights granted on an Offering Date exceeds the number of shares then
available under this Plan (after deduction of all shares for which Purchase
Rights have been exercised or are then outstanding), the Administrator shall
make a pro-rata allocation of the available shares in a manner that it
determines to be as uniform and equitable as practicable. In such event, the
Administrator shall give written notice of the reduction and allocation to each
Participant.


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          (c)  The Administrator may, in its discretion, transfer shares
reserved for issuance under this Plan into a plan or plans of similar terms, as
approved by the Board, providing for the purchase of shares of Common Stock to
employees of Subsidiaries designated by the Board that do not (or do not
thereafter) participate in this Plan. Such additional plans may, without
limitation, provide for variances from the terms of this Plan to take into
account special circumstances (such as foreign legal restrictions) affecting the
employees of the designated Subsidiaries.

     13.  Administration.

          This Plan shall be administered by the Board or by such directors,
officers, and employees of the Company as the Board may select from time to time
(the "Administrator"). All costs and expenses incurred in administering this
Plan shall be paid by the Company, provided that any taxes applicable to an
Employee's participation in this Plan may be charged to the Employee by the
Company. The Administrator may make such rules and reg ulations as it deems
necessary to administer this Plan and to interpret any provision of this Plan.
Any determination, decision, or action of the Administrator in connection with
the construction, interpretation, administration, or application of this Plan or
any right granted under this Plan shall be final, conclusive, and binding upon
all persons, and no member of the Administrator shall be liable for any such
determination, decision, or action.

     14.  Designation of Beneficiary.

          (a)  A Participant may file a written designation of a beneficiary who
is to receive any shares and cash, if any, from the Participant's account under
this Plan in the event of the Participant's death.

          (b)  A designation of beneficiary may be changed by the Participant at
any time by written notice. In the event of the death of a Participant, and in
the absence of a beneficiary validly designated under this Plan who is living at
the time of the Participant's death, the Administrator shall deliver such shares
and/or cash to the executor or administrator of the Participant's estate, or if
no such executor or administrator has been appointed (to the Administrator's
knowledge), the Administrator, in its discretion, may deliver such shares and/or
cash to the spouse or to any one or more dependents or relatives of the
Participant or, if no spouse, dependent, or relative is known to the
Administrator, then to such other person as the Administrator may designate.

     15.  Transferability.

          Neither payroll deductions credited to a Participant's account nor any
rights with regard to the exercise of a Purchase Right or to receive shares
under this Plan may be assigned, transferred, pledged, or otherwise disposed of
in any way (other than by will, the laws of descent and distribution or as
provided in Section 14) by the Participant. Any such attempt at assignment,
transfer, pledge, or other disposition shall be without effect, except that the
Administrator may treat such act as an election to withdraw funds in accordance
with Section 10.


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     16.  Reports.

          Individual accounts will be maintained for each Participant in this
Plan. Statements of account will be given to Participants promptly following
each Purchase Date, setting forth the amounts of payroll deductions, per-share
purchase price, number of shares purchased, and the remaining cash balance, if
any.

     17.  Adjustments upon Changes in Capitalization.

          (a)  Subject to any required action by the stockholders of the
Company, the number of shares of Common Stock covered by each Purchase Right
that has not yet been exercised and the number of shares of Common Stock that
have been authorized for issuance under this Plan but have not yet been placed
under a Purchase Right (collectively, the "Reserves"), as well as the price per
share of Common Stock covered by each Purchase Right that has not yet been
exercised, shall be proportionately adjusted for any increase or decrease in the
number of issued shares of Common Stock resulting from a stock split, reverse
stock split, stock dividend, combination or reclassification of the Common
Stock, or any other increase or decrease in the number of shares of Common Stock
effected without receipt of consideration by the Company; provided, however,
that conversion of any convertible securities of the Company shall not be deemed
to have been "effected without receipt of consideration." Such adjustment shall
be made by the Administrator, whose determination shall be final, binding, and
conclusive. Except as expressly provided herein, no issue by the Company of
shares of stock of any class, or securities convertible into shares of stock of
any class, shall affect, and no adjustment by reason thereof shall be made with
respect to, the number or price of shares of Common Stock subject to a Purchase
Right.

          (b)  In the event of the proposed dissolution or liquidation of the
Company, the then-current Offering Period will terminate immediately before the
consummation of such proposed action, unless otherwise provided by the Board or
the Administrator (if the Administrator is not the Board). In the event of a
proposed sale of all or substantially all of the assets of the Company, or the
merger of the Company with or into another corporation (if stockholders of the
Company own less than 50% of the total outstanding voting power in the surviving
entity or a parent of the surviving entity after the merger), each Purchase
Right shall be assumed or an equivalent purchase right shall be substituted by
the successor corporation or a parent or subsidiary of the successor
corporation, unless the successor corporation does not agree to assume the
Purchase Right or to substitute an equivalent purchase right, in which case the
Administrator may, in lieu of such assumption or substitution, accelerate the
exercisability of Purchase Rights and allow Purchase Rights to be exercisable
(if the Board approves) as to shares as to which the Purchase Right would not
otherwise be exercisable, on terms and for a period that the Administrator
determines in its discretion. To the extent that the Administrator accelerates
exercisability of Purchase Rights as described above, it shall promptly so
notify all Participants in writing.

          (c)  The Administrator may, in its discretion, also make provision for
adjusting the Reserves, as well as the price per share of Common Stock covered
by each outstanding


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Purchase Right, if the Company effects one or more reorganizations,
recapitalizations, rights offerings, or other increases or reductions of shares
of its outstanding Common Stock, or if the Company consolidates with or merges
into any other corporation.

     18.  Amendment or Termination.

          (a)  The Board may at any time terminate or amend this Plan. No
amendment may be made without prior approval of the stockholders of the Company
(obtained in the manner described in paragraph 20) if it would:

               (i)   Increase the number of shares that may be issued under this
                     Plan; or

               (ii)  Change the designation of the employees (or class of
                     employees) eligible for participation in this Plan.

          (b)  The Board may elect to terminate any or all outstanding Purchase
Rights at any time, except to the extent that exercisability of such Purchase
Rights has been accelerated pursuant to Section 17(b). If this Plan is
terminated, the Board may also elect to terminate Purchase Rights upon
completion of the next purchase of shares on the next Purchase Date or to permit
Purchase Rights to expire in accordance with their terms (with participation to
continue through such expiration dates). If Purchase Rights are terminated
before expiration, any funds contributed to this Plan that have not been used to
purchase shares shall be refunded to Participants as soon as administratively
feasible.

     19.  Notices.

          All notices or other communications by a Participant to the Company or
the Administrator under or in connection with this Plan shall be deemed to have
been duly given when received in the form specified by the Administrator at the
location, or by the person, designated by the Administrator for that purpose.

     20.  Stockholder Approval.

          This Plan shall be submitted to the stockholders of the Company for
their approval within 12 months after the date this Plan is adopted by the
Board.


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     21.  Conditions upon Issuance of Shares.

          (a)  Shares shall not be issued with respect to a Purchase Right
unless the exercise of such Purchase Right and the issuance and delivery of such
shares pursuant thereto shall comply with all applicable provisions of law,
domestic or foreign, including, without limitation, the Securities Act of 1933,
as amended, the Securities Exchange Act of 1934, as amended, the rules and
regulations promulgated thereunder, and the requirements of any stock exchange
upon which the shares may then be listed, and shall be further subject to the
approval of counsel for the Company with respect to such compliance.

          (b)  As a condition to the exercise of a Purchase Right, the Company
may require the person exercising such Purchase Right to represent and warrant
at the time of any such exercise that the shares are being purchased only for
investment and without any present intention to sell or distribute such shares
if, in the opinion of counsel for the Company, such a representation is required
by any of the aforementioned applicable provisions of law.

     22.  Term of Plan.

          This Plan shall become effective upon the earlier to occur of its
adoption by the Board of Directors or its approval by the stockholders of the
Company as described in Section 20. It shall continue in effect for a term of 20
years unless sooner terminated under Section 19.


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