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                                                                   EXHIBIT 10.31

                                                                   NO. CW - ____

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED (THE "ACT"), OR UNDER THE SECURITIES LAWS OF ANY STATE.
THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE AND
MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER THE ACT AND
APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION
THEREFROM. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN
FORM AND SUBSTANCE REASONABLY SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY
PROPOSED TRANSFER OR RESALE IS IN COMPLIANCE WITH THE ACT AND ANY APPLICABLE
STATE SECURITIES LAWS.

                           WARRANT TO PURCHASE SHARES
                               OF COMMON STOCK OF
                       INTRABIOTICS PHARMACEUTICALS, INC.
                          (VOID AFTER OCTOBER __, 2008)

         This certifies that ________________________, or its permitted assigns
(the "Holder"), for value received, is entitled to purchase from INTRABIOTICS
PHARMACEUTICALS, INC., a Delaware corporation (the "Company"), having a place of
business at 2483 East Bayshore Road, Suite 100, Palo Alto, California 94303,
such aggregate maximum number of fully paid and nonassessable shares of the
Company's Common Stock ("Common Stock") as would be obtained in accordance with
the formula set forth below at an exercise price (the "Exercise Price") equal to
the Stock Purchase Price (as defined in that certain Common Stock and Warrant
Purchase Agreement (the "Purchase Agreement"), dated as of October 6, 2003 (the
"Definitive Agreement Date"), between the Holder and the Company ) at any time
or from time to time, subject to Section 1.1 hereof, up to and including 5:00
p.m. (Pacific time) on October __, 2008 (the "Expiration Date") upon surrender
to the Company at its principal office (or at such other location as the Company
may advise the Holder in writing) of this Warrant properly endorsed with the
Form of Subscription attached hereto duly filled in and signed and upon payment
in cash or wire transfer of the aggregate Exercise Price for the number of
shares for which this Warrant is being exercised determined in accordance with
the provisions hereof. The aggregate number of shares subject to this Warrant
shall be equal to (i) 20% of the Holder's aggregate purchase price for the
shares of Common Stock as set forth on the Signature Page (as defined in the
Purchase Agreement) divided by (ii) the Stock Purchase Price. The Exercise Price
and the number of shares purchasable hereunder are subject to adjustment as
provided in Section 3 of this Warrant. As used herein, the term "Original Issue
Date" shall mean the issuance date of this Warrant.

         This Warrant is subject to the following terms and conditions:

         1.       EXERCISE; ISSUANCE OF CERTIFICATES; PAYMENT FOR SHARES.

                  1.1      GENERAL. This Warrant is exercisable at the option of
the Holder of record hereof, at any time or from time to time, up to the
Expiration Date for all or any part of the shares

                                       1.

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of Common Stock (but not for a fraction of a share) which may be purchased
hereunder. The Company agrees that the shares of Common Stock purchased under
this Warrant shall be and are deemed to be issued to the Holder hereof as the
record owner of such shares as of the close of business on the date on which
this Warrant shall have been surrendered, properly endorsed, the completed,
executed Form of Subscription delivered and payment made for such shares.
Certificates for the shares of Common Stock so purchased, together with any
other securities or property to which the Holder hereof is entitled upon such
exercise, shall be delivered to the Holder hereof by the Company at the
Company's expense within a reasonable time after the rights represented by this
Warrant have been so exercised. In case of a purchase of less than all the
shares which may be purchased under this Warrant, the Company shall cancel this
Warrant and execute and deliver a new Warrant or Warrants of like tenor for the
balance of the shares purchasable under the Warrant surrendered upon such
purchase to the Holder hereof within a reasonable time. Each stock certificate
so delivered shall be in such denominations of Common Stock as may be requested
by the Holder hereof and shall be registered in the name of such Holder or in
the name of Holder's affiliate and/or subsidiary as may be requested by the
Holder.

                  1.2      NET ISSUE EXERCISE. Notwithstanding any provisions
herein to the contrary, if the fair market value of one share of the Company's
Common Stock is greater than the Exercise Price (at the date of calculation as
set forth below), in lieu of exercising this Warrant for cash, the Holder may
elect to receive shares equal to the value (as determined below) of this Warrant
(or the portion thereof being canceled) by surrender of this Warrant at the
principal office of the Company together with the properly endorsed Form of
Subscription with notice of such election in which event the Company shall issue
to the Holder a number of shares of Common Stock computed using the following
formula:

                           X = Y(A-B)
                               ------
                                 A

         Where X = the number of shares of Common Stock to be issued to the
Holder

                                    Y = the number of shares of Common Stock
                                    purchasable under the Warrant or, if only a
                                    portion of the Warrant is being exercised,
                                    the portion of the Warrant being canceled
                                    (at the date of such calculation)

                                    A =    the fair market value of one share of
                                    the Company's Common Stock (at the date of
                                    such calculation)

                                    B =    Exercise Price (as adjusted to the
                                    date of such calculation)

         For purposes of the above calculation, if the Common Stock is traded on
any established stock exchange or traded on the Nasdaq National Market or the
Nasdaq SmallCap Market, then the fair market value of one share of Common Stock
shall be the closing sales price for such stock (or the closing bid, if no sales
were reported) as quoted on such exchange or market (or the exchange or market
with the greatest volume of trading in the Common Stock) on the last market

                                       2.

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trading day prior to the day of determination, as reported in The Wall Street
Journal or, if not reported in The Wall Street Journal, then such other source
as the Company's Board of Directors reasonably deems reliable. In the absence of
such markets for Common Stock, the fair market value of one share of Common
Stock shall be determined by the Company's Board of Directors in good faith;
provided, however, upon the written request of the Investor, the Company shall
appoint an independent appraiser which shall be reasonably satisfactory to the
Investor, to prepare an independent appraisal of the fair market value of one
share of Common Stock. The expenses of any appraisal by such independent
appraiser shall be borne by the Company.

         The "net issue exercise" of this Warrant pursuant to this Section 1.2
is intended to qualify as a recapitalization within the meaning of Section
368(a)(1)(E) of the Internal Revenue Code of 1986, as amended.

         2.       SHARES TO BE FULLY PAID; RESERVATION OF SHARES. The Company
covenants and agrees that all shares of Common Stock which may be issued upon
the exercise of the rights represented by this Warrant will, upon issuance, be
duly authorized, validly issued, fully paid and nonassessable and free from all
preemptive rights of any stockholder and free of all taxes, liens and charges
with respect to the issue thereof. The Company further covenants and agrees
that, during the period within which the rights represented by this Warrant may
be exercised, the Company will at all times have authorized and reserved, for
the purpose of issue or transfer upon exercise of the subscription rights
evidenced by this Warrant, a sufficient number of shares of authorized but
unissued Common Stock, or other securities and property, when and as required to
provide for the exercise of the rights represented by this Warrant. The Company
will take all such action as may be necessary to assure that such shares of
Common Stock may be issued as provided herein without violation of any
applicable law or regulation, or of any requirements of any securities exchange
upon which the Common Stock may be listed; provided, however, that, except as
required by the Purchase Agreement, the Company shall not be required to effect
a registration under federal or state securities laws solely because of such
exercise. The Company will not take any action which would result in any
adjustment of the Exercise Price (as set forth in Section y3 hereof) if the
total number of shares of Common Stock issuable after such action upon exercise
of all outstanding warrants, together with all shares of Common Stock then
outstanding and all shares of Common Stock then issuable upon exercise of all
options and upon the conversion of all convertible securities then outstanding,
would exceed the total number of shares of Common Stock then authorized by the
Company's Certificate of Incorporation.

         3.       ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF SHARES. The
Exercise Price and the number of shares purchasable upon the exercise of this
Warrant shall be subject to adjustment from time to time upon the occurrence of
certain events described in this Section 3. Upon each adjustment of the Exercise
Price, the Holder of this Warrant shall thereafter be entitled to purchase, at
the Exercise Price resulting from such adjustment, the number of shares obtained
by multiplying the Exercise Price in effect immediately prior to such adjustment
by the number of shares purchasable pursuant hereto immediately prior to such
adjustment, and dividing the product thereof by the Exercise Price resulting
from such adjustment.

                  3.1      SUBDIVISION OR COMBINATION OF STOCK. In case the
Company shall at any time subdivide its outstanding shares of Common Stock into
a greater number of shares, the

                                       3.

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Exercise Price in effect immediately prior to such subdivision shall be
proportionately reduced, and conversely, in case the outstanding shares of
Common Stock of the Company shall be combined into a smaller number of shares,
the Exercise Price in effect immediately prior to such combination shall be
proportionately increased.

                  3.2      DIVIDENDS IN COMMON STOCK, OTHER STOCK, PROPERTY,
RECLASSIFICATION. If at any time or from time to time the holders of Common
Stock (or any shares of stock or other securities at the time receivable upon
the exercise of this Warrant) shall have received or become entitled to receive,
without payment therefor,

                           (a)      Common Stock or any shares of stock or other
securities which are at any time directly or indirectly convertible into or
exchangeable for Common Stock, or any rights or options to subscribe for,
purchase or otherwise acquire any of the foregoing by way of dividend or other
distribution,

                           (b)      any cash paid or payable otherwise than as a
cash dividend, or

                           (c)      Common Stock or additional stock or other
securities or property (including cash) by way of spinoff, split-up,
reclassification, combination of shares or similar corporate rearrangement,
(other than shares of Common Stock issued as a stock split or adjustments in
respect of which shall be covered by the terms of Section 3.1 above),

then and in each such case, the Holder hereof shall, upon the exercise of this
Warrant, be entitled to receive, in addition to the number of shares of Common
Stock receivable thereupon, and without payment of any additional consideration
therefor, the amount of stock and other securities and property (including cash
in the cases referred to in clauses y(b) and y(c) above) which such Holder would
hold on the date of such exercise had he been the holder of record of such
Common Stock as of the date on which holders of Common Stock received or became
entitled to receive such shares or all other additional stock and other
securities and property.

                  3.3      REORGANIZATION, RECLASSIFICATION, CONSOLIDATION,
MERGER OR SALE. If any recapitalization, reclassification or reorganization of
the capital stock of the Company, or any consolidation or merger of the Company
with another corporation, or the sale of all or substantially all of its assets
or other transaction shall be effected in such a way that holders of Common
Stock shall be entitled to receive stock, securities, or other assets or
property (an "Organic Change"), then, as a condition of such Organic Change,
lawful and adequate provisions shall be made by the Company whereby the Holder
hereof shall thereafter have the right to purchase and receive (in lieu of the
shares of the Common Stock of the Company immediately theretofore purchasable
and receivable upon the exercise of the rights represented hereby) such shares
of stock, securities or other assets or property as may be issued or payable
with respect to or in exchange for a number of outstanding shares of such Common
Stock equal to the number of shares of such stock immediately theretofore
purchasable and receivable upon the exercise of the rights represented hereby.
In the event of any Organic Change, appropriate provision shall be made by the
Company with respect to the rights and interests of the Holder of this Warrant
to the end that the provisions hereof (including, without limitation, provisions
for adjustments of the Exercise Price and of the number of shares purchasable
and receivable upon the exercise of this

                                       4.

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Warrant) shall thereafter be applicable, in relation to any shares of stock,
securities or assets thereafter deliverable upon the exercise hereof. The
Company will not effect any such consolidation, merger or sale unless, prior to
the consummation thereof, the successor corporation (if other than the Company)
resulting from such consolidation or merger or the corporation purchasing such
assets shall assume by written instrument the obligation to deliver to such
Holder such shares of stock, securities or assets as, in accordance with the
foregoing provisions, such Holder may be entitled to purchase.

                  3.4      CERTAIN EVENTS. If any change in the outstanding
Common Stock of the Company or any other event occurs as to which the other
provisions of this Section y3 are not strictly applicable or if strictly
applicable would not fairly protect the purchase rights of the Holder of the
Warrant in accordance with such provisions, then the Board of Directors of the
Company shall make an adjustment in the number and class of shares available
under the Warrant, the Exercise Price or the application of such provisions, so
as to protect such purchase rights as aforesaid. The adjustment shall be such as
will give the Holder of the Warrant upon exercise for the same aggregate
Exercise Price the total number, class and kind of shares as such Holder would
have owned had the Warrant been exercised prior to the event and had such Holder
continued to hold such shares until after the event requiring adjustment.

                  3.5      NOTICES OF CHANGE.

                           (a)      Immediately upon any adjustment in the
number or class of shares subject to this Warrant and of the Exercise Price, the
Company shall give written notice thereof to the Holder, setting forth in
reasonable detail and certifying the calculation of such adjustment.

                           (b)      The Company shall give written notice to the
Holder at least ten (10) calendar days prior to the date on which the Company
closes its books or takes a record for determining rights to receive any
dividends or distributions or any right to subscribe for, purchase or otherwise
acquire any shares of stock of any class or any other securities or property, or
to receive any other right.

                           (c)      The Company shall give written notice to the
Holder at least ten (10) calendar days prior to the date on which an Organic
Change shall take place, including in such notice the date as of which the
Organic Change is expected to become effective and the date as of which it is
expected that holders of Common Stock of record shall be entitled to exchange
their shares of Common Stock for securities or other property, if any,
deliverable upon such Organic Change.

                           (d)      The Company shall initiate the delivery of
written notice to the Holder of any voluntary or involuntary dissolution,
liquidation or winding-up of the Company (the "Dissolution") on the date such
Dissolution is publicly announced, including in such notice the date as of which
the Dissolution is expected to become effective and the date as of which it is
expected that holders of Common Stock of record shall be entitled to exchange
their shares of Common Stock for securities or other property, if any.

                                       5.

<PAGE>

         4.       LISTING. The Company shall file any forms and do any acts as
shall be required from time to time to secure the listing or quotation of the
Common Stock issuable upon exercise of the Warrant with each national securities
exchange or automated quotation system, if any, upon which shares of such
securities are then listed or traded and shall use its commercially reasonable
efforts to maintain, so long as any other shares of such securities shall be so
listed or traded, such listing or quotation of all securities issued or issuable
upon the exercise of this Warrant.

         5.       ISSUE TAX. The issuance of certificates for shares of Common
Stock upon the exercise of the Warrant shall be made without charge to the
Holder of the Warrant for any issue tax (other than any applicable income taxes)
in respect thereof; provided, however, that the Company shall not be required to
pay any tax which may be payable in respect of any transfer involved in the
issuance and delivery of any certificate in a name other than that of the then
Holder of the Warrant being exercised.

         6.       CLOSING OF BOOKS. The Company will at no time close its
transfer books against the transfer of any warrant or of any shares of Common
Stock issued or issuable upon the exercise of any warrant in any manner which
interferes with the timely exercise of this Warrant.

         7.       NO VOTING OR DIVIDEND RIGHTS; LIMITATION OF LIABILITY. Nothing
contained in this Warrant shall be construed as conferring upon the Holder
hereof the right to vote or to consent or to receive notice as a stockholder of
the Company or any other matters or any rights whatsoever as a stockholder of
the Company. No dividends or interest shall be payable or accrued in respect of
this Warrant or the interest represented hereby or the shares purchasable
hereunder until, and only to the extent that, this Warrant shall have been
exercised. No provisions hereof, in the absence of affirmative action by the
Holder to purchase shares of Common Stock, and no mere enumeration herein of the
rights or privileges of the Holder hereof, shall give rise to any liability of
such Holder for the Exercise Price or as a stockholder of the Company, whether
such liability is asserted by the Company or by its creditors.

         8.       REPRESENTATIONS OF HOLDER. Holder represents that it has all
necessary power and authority to execute and deliver this Warrant. Holder
further represents that it understands that neither this Warrant nor the shares
of Common Stock issuable upon the exercise thereof have been registered under
the Act, and are being offered pursuant to an exemption from registration
contained in the Act based in part upon Holder's representations contained in
this Section y8. Holder represents that by reason of its own, or of its
management's, knowledge and experience in financial and business matters, Holder
is capable of evaluating the merits and risks of its investment in the Company
and has the capacity to protect its own interests in connection with the
issuance of this Warrant and the shares of Common Stock issuable upon the
exercise thereof, and is able to bear risk, including a complete loss, of the
investment. Holder represents that it is an "accredited investor" within the
meaning set forth in Regulation D under the Act. Holder represents that it is
acquiring such securities for its own account for investment only, and not with
a view towards their distribution.

         9.       TRANSFERABILITY. This Warrant is not transferable except to an
affiliate of Holder; provided that Holder provides prior written notice of such
transfer to the Company, such transferee agrees to be bound by the obligations
hereunder, and the Company may treat such

                                       6.

<PAGE>

transferee as the absolute owner hereof for any purpose and as the person
entitled to exercise the rights represented by this Warrant.

         10.      RIGHTS AND OBLIGATIONS SURVIVE EXERCISE OF WARRANT. The rights
and obligations of the Company, of the Holder of this Warrant and of the holder
of shares of Common Stock issued upon exercise of this Warrant, shall survive
the exercise of this Warrant.

         11.      MODIFICATION AND WAIVER. This Warrant and any provision hereof
may be changed, waived, discharged or terminated only by an instrument in
writing signed by the party against which enforcement of the same is sought.

         12.      NOTICES. Any notice, request or other document required or
permitted to be given or delivered to the Holder hereof or the Company shall be
in writing, shall refer specifically to this Warrant and shall be personally
delivered or shall be sent by certified mail or internationally recognized
overnight courier, postage prepaid, to Holder at its address as shown on the
signature page hereto or to the Company at the address indicated therefor in the
first paragraph of this Warrant or such other address as either may from time to
time provide to the other in writing. Any delivery, notice, request or other
document given in conformity with this Section 12 shall be deemed to be
effective when received by the addressee.

         13.      BINDING EFFECT ON SUCCESSORS. This Warrant shall be binding
upon any corporation succeeding the Company by merger, consolidation or
acquisition of all or substantially all of the Company's assets. All of the
covenants and agreements of the Company shall inure to the benefit of the
successors and permitted assigns of the Holder hereof.

         14.      DESCRIPTIVE HEADINGS AND GOVERNING LAW. The description
headings of the several sections and paragraphs of this Warrant are inserted for
convenience only and do not constitute a part of this Warrant. This Warrant
shall be construed and enforced in accordance with, and the rights of the
parties shall be governed by, the laws of the State of California.

         15.      LOST WARRANTS. The Company represents and warrants to the
Holder hereof that upon receipt of evidence reasonably satisfactory to the
Company of the loss, theft, destruction, or mutilation of this Warrant and, in
the case of any such loss, theft or destruction, upon receipt of an indemnity
reasonably satisfactory to the Company, or in the case of any such mutilation
upon surrender and cancellation of such Warrant, the Company, at its expense,
will make and deliver a new Warrant, of like tenor, in lieu of the lost, stolen,
destroyed or mutilated Warrant.

         16.      FRACTIONAL SHARES. No fractional shares shall be issued upon
exercise of this Warrant. The Company shall, in lieu of issuing any fractional
share, pay the Holder entitled to such fraction a sum in cash equal to such
fraction multiplied by the then effective Exercise Price.

                      [THIS SPACE INTENTIONALLY LEFT BLANK]

                                       7.

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         IN WITNESS WHEREOF, the Company has caused this Warrant to be duly
executed by its officers, thereunto duly authorized this ___ day of ___________,
2003.

                                  INTRABIOTICS PHARMACEUTICALS, INC.

                                  By:_____________________________________
                                      Eric H. Bjerkholt
                                      Senior Vice President and Chief
                                      Financial Officer

HOLDER:

________________________________

By:_____________________________

Print Name:_____________________

Title:__________________________

Address:________________________
        ________________________
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                                SUBSCRIPTION FORM

                                                  Date: _________________, 200_

IntraBiotics Pharmaceuticals, Inc.
2483 East Bayshore Road
Palo Alto, CA 94303
Attn: Chief Financial Officer

Ladies and Gentlemen:

[ ]      The undersigned hereby elects to exercise the warrant issued to it by
         IntraBiotics Pharmaceuticals, Inc. (the "Company") and dated
         _______________, 2003 Warrant No. CW-___ (the "Warrant") and to
         purchase thereunder __________________________________ shares of the
         Common Stock of the Company (the "Shares") at a purchase price of $____
         per Share or an aggregate purchase price of ________________ Dollars
         ($__________) (the "Purchase Price").

[ ]      The undersigned hereby elects to convert ______________________ percent
         (___%) of the value of the Warrant pursuant to the provisions of
         Section 1.2 of the Warrant.

Pursuant to the terms of the Warrant the undersigned has delivered the Purchase
Price herewith in full in cash or wire transfer.

                                   Very truly yours,

                                   _____________________________________________
                                         Print Entity Name, if applicable

                                   By:__________________________________________

                                   Print Name:__________________________________

                                   Title:_______________________________________