Document:

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                                                                    EXHIBIT 4.26

                               BIOPURE CORPORATION

                                     WARRANT

Warrant No. __                                          Dated: December __, 2006

      Biopure Corporation, a Delaware corporation (the "COMPANY"), hereby
certifies that, for value received, _______ or its registered assigns (including
permitted transferees, the "HOLDER"), as registered owner of this warrant (the
"WARRANT"), is entitled to purchase from the Company up to a total of ______
shares (as adjusted from time to time as provided in Section 9) of Common Stock
(as defined below), together with the associated preferred stock purchase rights
under that certain Rights Agreement (the "RIGHTS AGREEMENT") dated as of
September 24, 1999 between the Company and American Stock Transfer & Trust
Company, as rights agent, to the extent the Rights Agreement is in effect on the
date of such purchase, at an exercise price equal to $____ per share (as
adjusted from time to time as provided in Section 9, the "EXERCISE PRICE") (125%
of the public offering price per unit), at any time and from time to time from
and after December __, 2007 (the "INITIAL EXERCISE DATE") to and including
December __, 2011 (the "EXPIRATION DATE"), and subject to the following terms
and conditions.

      1. Definitions. The capitalized terms used herein and not otherwise
defined shall have the meanings set forth below:

            "AFFILIATE" of any specified Person means any other person or entity
directly or indirectly controlling, controlled by or under direct or indirect
common control with such specified Person. For purposes of this definition,
"CONTROL" means the power to direct the management and policies of such Person
or firm, directly or indirectly, whether through the ownership of voting
securities, by contract or otherwise.

            "COMMISSION" means the United States Securities and Exchange
Commission.

            "COMMON STOCK" means the Class A common stock of the Company, $0.01
par value per share.

            "ELIGIBLE MARKET" means any of the New York Stock Exchange, the
American Stock Exchange or Nasdaq (as defined below), and any successor markets
thereto.

            "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended

            "MARKET PRICE" shall mean (i) if the principal trading market for
such securities is an exchange, the average of the last reported sale prices per
share for the last ten previous Trading Days in which a sale was reported, as
officially reported on any consolidated tape, (ii) if clause (i) is not
applicable, the average of the closing bid price per share for the last ten
previous Trading Days as set forth by Nasdaq or (iii) if clauses (i) and (ii)
are not applicable, the average of the closing bid price per share for the last
ten previous Trading Days as set forth in the National Quotation Bureau sheet
listing for such securities. Notwithstanding the foregoing, if there is no
reported sales price or closing bid price, as the case may be, on any of the ten
Trading Days preceding the event requiring a determination of Market Price
hereunder, then the Market

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Price shall be determined in good faith after reasonable investigation by
resolution of the Board of Directors of the Company.

            "NASDAQ" means the Nasdaq Global Market or Nasdaq Capital Market,
and any successor markets thereto.

            "OTHER SECURITIES" refers to any capital stock (other than Common
Stock) and other securities of the Company or any other Person which the Holder
of this Warrant at any time shall be entitled to receive, or shall have
received, pursuant to the terms hereof upon the exercise of this Warrant, in
lieu of or in addition to Common Stock.

            "PERSON" means any court or other federal, state, local or other
governmental authority or other individual or corporation, partnership, trust,
incorporated or unincorporated association, joint venture, limited liability
company, joint stock company, government (or an agency or subdivision thereof)
or other entity of any kind.

            "REGISTRATION STATEMENT" means the Company's Registration Statement
on Form S-1 (File No. 333-138049), as such registration statement is amended,
supplemented or replaced.

            "TRADING DAY" means (a) any day on which the Common Stock is listed
or quoted and traded on any Eligible Market or (b) if the Common Stock is not
then quoted and traded on any Eligible Market, then a day on which trading
occurs on the Nasdaq Global Market (or any successor thereto).

            "WARRANT SHARES" shall initially mean shares of Common Stock
(together with the associated preferred stock purchase rights under the Rights
Agreement to the extent the Rights Agreement is in effect on the applicable
date) and in addition may include Other Securities and Substituted Property (as
defined in Section 9(e)(x)) issued or issuable from time to time upon exercise
of this Warrant.

      2. Registration of Warrant. The Company shall register this Warrant, upon
records to be maintained by the Company for that purpose (the "WARRANT
REGISTER"), in the name of the record Holder hereof from time to time. The
Company may deem and treat the registered Holder of this Warrant as the absolute
owner hereof for the purpose of any exercise hereof or any distribution to the
Holder, and for all other purposes.

      3. Registration of Transfers. The Company shall register the transfer of
any portion of this Warrant in the Warrant Register, upon surrender of this
Warrant, with the Form of Assignment attached hereto as Appendix A duly
completed and signed, to the Company at its address specified herein. Upon any
such registration and transfer, a new warrant in substantially the form of a
Warrant (any such new warrant, a "NEW WARRANT"), evidencing the portion of this
Warrant so transferred shall be issued to the transferee and a New Warrant
evidencing the remaining portion of this Warrant not so transferred, if any,
shall be issued to the transferring Holder. The acceptance of the New Warrant by
the transferee thereof shall be deemed the acceptance by such transferee of all
of the rights and obligations of a holder of a Warrant.

      The registered Holder of this Warrant, by its acceptance hereof, agrees
that, for a period commencing on the date hereof and ending one hundred eighty
(180) days after the effective date of the Registration Statement, inclusive
(the "LOCK-UP PERIOD"), it will not sell, transfer or assign or hypothecate this
Warrant to anyone other than (i) an officer or partner of such Holder,

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(ii) an officer of either Dawson James Securities, Inc. or [_______], the
underwriters of the public offering with respect to which this Warrant has been
issued ("UNDERWRITERS") or an officer or partner of any selected dealer in
connection with the Company's public offering with respect to which this Warrant
has been issued, or (iii) any selected dealer. Following the Lock-Up Period,
transfers to others may be made subject to compliance with or exemptions from
applicable securities laws. In order to make any permitted assignment, the
Holder must deliver to the Company the assignment form attached hereto duly
executed and completed, together with the Warrant and payment of all transfer
taxes, if any, payable in connection therewith. The Company shall immediately
transfer this Warrant on the books of the Company and shall execute and deliver
a new Warrant of like tenor to the appropriate assignee(s) expressly evidencing
the right to purchase the aggregate number of Warrant Shares purchasable
hereunder or such portion of such number as shall be contemplated by any such
assignment.

      4. Exercise and Duration of Warrant.

         (a) This Warrant shall be exercisable, either in its entirety or for a
portion of the number of Warrant Shares, by the registered Holder at any time
and from time to time from and after the Initial Exercise Date to and including
the Expiration Date. At 5:00 P.M. New York City time on the Expiration Date, the
portion of this Warrant not exercised prior thereto shall be and become void and
of no value, and the Holder hereof shall have no right to purchase any
additional Warrant Shares hereunder.

         (b) A Holder may exercise this Warrant by delivering to the Company, in
accordance with Section 13, this Warrant, together with (i) an exercise notice,
in the form attached hereto as Appendix B (the "EXERCISE NOTICE"), appropriately
completed and duly signed, and (ii) payment of the Exercise Price for the number
of Warrant Shares as to which this Warrant is being exercised (as set forth in
Section 4(c) below), and the date such items are received by the Company is an
"EXERCISE DATE." Execution and delivery of an Exercise Notice in respect of less
than all of the Warrant Shares issuable upon exercise of this Warrant shall
result in the cancellation of the original Warrant and issuance of a New Warrant
evidencing the right to purchase the remaining number of Warrant Shares.

         (c) The Holder shall pay the Exercise Price in cash, by certified bank
check payable to the order of the Company or by wire transfer of immediately
available funds in accordance with the Company's instructions.

         (d) Except as otherwise provided for herein, this Warrant shall not
entitle the Holder to any voting rights or other rights as a stockholder of the
Company by virtue of the ownership hereof.

         (e) Notwithstanding anything to the contrary herein, after the sixth
(6th) month anniversary of the date hereof, the Company may, by written notice
to the Holder, require that the Holder execute and deliver to the Company an
Exercise Notice exercising all of the Warrant Shares then held by such Holder
within twenty Business Days of the date of the Company's notice; provided,
however, that the Company may only provide such notice if the daily volume
weighted average price per share of the Common Stock for each of the ten
consecutive Trading Days ended immediately prior to the Company's notice is
equal to or greater than the Exercise Price multiplied by 1.5. At 5:00 P.M. New
York City time on such 20th Business Day, the portion of this Warrant not
exercised prior thereto shall be and become void and of no value, and the Holder
hereof shall have no right to purchase any additional Warrant Shares hereunder.

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      5. Delivery of Warrant Shares.

         (a) Upon exercise of this Warrant, the Company shall promptly issue or
cause to be issued and deliver or cause to be delivered to the Holder, in such
name or names as the Holder may designate, a certificate for the Warrant Shares
issuable upon such exercise (the "CERTIFICATE") bearing no restrictive legends.
The Holder, or any Person so designated by the Holder to receive the Warrant
Shares, shall be deemed to have become holder of record of such Warrant Shares
as of the Exercise Date.

         (b) The Warrant and the Warrant Shares have been registered pursuant to
the Registration Statement, and the Company covenants and agrees to maintain the
effectiveness of the Registration Statement until the Expiration Date.
Notwithstanding the foregoing, in the event that, prior to the Expiration Date,
the Company ceases to be eligible under the Securities Act of 1933, as amended
(the "ACT") or the rules and regulations promulgated thereunder, to maintain a
registration statement on Form S-1, or in the event that the Warrant or the
Warrant Shares cease to be eligible for inclusion in such Registration Statement
to the extent necessary to permit the Holder to exercise the Warrant and sell
the Warrant Shares without restriction under the Act, the Company will promptly
(and in any event within 10 days of the date that the Warrant or any Warrant
Shares cease to be so eligible), amend or file a new registration statement
under the Act on a form eligible for use by the Company for the registration of
such securities and use its best efforts to have such registration statement
declared effective by the Commission as soon as practicable after such filing,
which registration statement shall include such information as may be required
to permit the exercise of the Warrant and the sale of the Warrant Shares without
restriction under the Act. The Holder acknowledges and agrees that the Warrant
shall be exercisable pursuant to any such registration statement only at such
times as the registration statement is effective or in accordance with any
applicable exemption from the registration requirements of the Act. Upon such
Registration Statement being declared effective by the Commission, the Company
shall use its best efforts to cause the Registration Statement to remain
effective for a period of at least six (6) consecutive months from the date that
the Holders of the Warrants and Warrant Shares covered by such Registration
Statement are first given the opportunity to sell all of such securities. In the
event that ninety (90) days prior to the Expiration Date, the Registration
Statement registering the Warrant Shares is not effective or is withdrawn or the
Commission issues a stop order suspending the effectiveness of such Registration
Statement, the Company hereby agrees to extend the Expiration Date for (x) an
additional ninety (90) days or (y) until the Registration Statement is declared
effective by the Commission, whichever period is longer. During such time as the
Warrant Shares are registered pursuant to any registration statement under the
Act, the Company further covenants and agrees to make timely filings of all
documents required to be filed under the Act or the Exchange Act in order to
ensure that the registration statement, including the documents incorporated by
reference therein, if any, do not contain an untrue statement of a material fact
or omit to state any material fact required to be stated therein or necessary in
order to make the statements therein not misleading.

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         (c) This Warrant is exercisable, either in its entirety or, from time
to time, for a portion of the number of Warrant Shares. Upon surrender of this
Warrant following one or more partial exercises, the Company shall issue or
cause to be issued, at its expense, a New Warrant evidencing the right to
purchase the remaining number of Warrant Shares.

      6. Charges, Taxes and Expenses. Issuance and delivery of certificates for
shares of Common Stock upon exercise of this Warrant shall be made without
charge to the Holder for any issue or transfer tax, withholding tax, transfer
agent fee or other incidental tax or expense in respect of the issuance of such
certificates, all of which taxes and expenses shall be paid by the Company;
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 issue, delivery or
registration of any certificates for Warrant Shares or Warrant in a name other
than that of the Holder and that the Holder will be required to pay any tax with
respect to cash received in lieu of fractional shares. The Holder shall be
responsible for all other tax liability that may arise as a result of holding or
transferring this Warrant or receiving Warrant Shares upon exercise hereof.

      7. Replacement of Warrant. If this Warrant is mutilated, lost, stolen or
destroyed, the Company, at the sole expense of the Holder (such expenses, if any
imposed by the Company to be reasonable), shall issue or cause to be issued in
exchange and substitution for and upon cancellation hereof, or in lieu of and in
substitution for this Warrant, a New Warrant, but only upon receipt of evidence
reasonably satisfactory to the Company of such loss, theft or destruction and
customary and reasonable indemnity, if requested by the Company.

      8. Reservation of Warrant Shares. The Company covenants that it will at
all times reserve and keep available out of the aggregate of its authorized but
unissued and otherwise unreserved Common Stock, solely for the purpose of
enabling it to issue Warrant Shares upon exercise of this Warrant as herein
provided, the number of Warrant Shares which are then issuable and deliverable
upon the exercise of this entire Warrant, free from all taxes, liens, claims,
encumbrances with respect to the issuance of such Warrant Shares and will not be
subject to any pre-emptive rights or similar rights (taking into account the
adjustments and restrictions of Section 9 hereof). The Company covenants that
all Warrant Shares so issuable and deliverable shall, upon issuance and the
payment of the applicable Exercise Price in accordance with the terms hereof, be
duly and validly authorized, issued, fully paid and nonassessable. 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
or automated quotation system upon which the Common Stock may be listed or
quoted, as the case may be; provided, however, that such actions shall only
require the Company's best efforts (or other specified standard) to the extent
specifically provided for in this Warrant.

      9. Certain Adjustments. The Exercise Price and number of Warrant Shares
issuable upon exercise of this Warrant are subject to adjustment from time to
time as set forth in this Section 9.

         (a) Stock Dividends. If the Company, at any time while this Warrant is
outstanding, pays a dividend on its Common Stock payable in additional shares of
Common Stock or otherwise makes a distribution on any class of capital stock
that is payable in shares of Common Stock, then in each such case the Exercise
Price shall be multiplied by a fraction, (A) the numerator of which shall be the
number of shares of Common Stock outstanding immediately prior to the opening of
business on the day after the record date for the determination of

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stockholders entitled to receive such dividend or distribution and (B) the
denominator of which shall be the number of shares of Common Stock outstanding
immediately after the distribution date of such dividend or distribution. Any
adjustment made pursuant to this Section 9(a) shall become effective immediately
after the record date for the determination of stockholders entitled to receive
such dividend or distribution; provided, however, that if following such record
date the Company rescinds or modifies such dividend or distribution, the
Exercise Price shall be appropriately adjusted (as of the date that the Company
effectively rescinds or modifies such dividend or distribution) to take into
account the effect of such rescinded or modified dividend or distribution on the
Exercise Price pursuant to this Section 9(a).

         (b) Stock Splits. If the Company, at any time while this Warrant is
outstanding, (i) subdivides outstanding shares of Common Stock into a larger
number of shares, or (ii) combines outstanding shares of Common Stock into a
smaller number of shares, then in each such case the Exercise Price shall be
multiplied by a fraction, (A) the numerator of which shall be the number of
shares of Common Stock outstanding immediately before such event and (B) the
denominator of which shall be the number of shares of Common Stock outstanding
immediately after such event. Any adjustment pursuant to this Section 9(b) shall
become effective immediately after the effective date of such subdivision or
combination.

         (c) Reclassifications. A reclassification of the Common Stock (other
than any such reclassification in connection with a merger or consolidation to
which Section 9(e) applies) into shares of any other class of stock shall be
deemed:

            (i) a distribution by the Company to the holders of its Common Stock
of such shares of such other class of stock for the purposes and within the
meaning of this Section 9; and

            (ii) if the outstanding shares of Common Stock shall be changed into
a larger or smaller number of shares of Common Stock as part of such
reclassification, such change shall be deemed a subdivision or combination, as
the case may be, of the outstanding shares of Common Stock for the purposes and
within the meaning of Section 9(b).

         (d) Other Distributions. If the Company, at any time while this Warrant
is outstanding, distributes to holders of Common Stock (i) evidences of its
indebtedness, (ii) shares of any class of capital stock, (iii) rights or
warrants to subscribe for or purchase any shares of any class of capital stock
or (iv) any other asset, other than a distribution of Common Stock covered by
Section 9(a), (in each case, "DISTRIBUTED PROPERTY"), then in each such case the
Exercise Price in effect immediately prior to the record date fixed for
determination of stockholders entitled to receive such distribution (and the
Exercise Price thereafter applicable) shall be adjusted (effective on and after
such record date) to equal the product of such Exercise Price multiplied by a
fraction, (A) the numerator of which shall be Market Price on such record date
less the then fair market value of the Distributed Property distributed in
respect of one outstanding share of Common Stock, which, if the Distributed
Property is other than cash or marketable securities, shall be as determined in
good faith by the Board of Directors of the Company whose determination shall be
described in a board resolution, and (B) the denominator of which shall be the
Market Price on such record date; provided, however, that if following the
record date for such distribution the Company rescinds or modifies such
distribution, the Exercise Price shall be appropriately adjusted (as of the date
that the Company effectively rescinds or modifies such distribution) to take
into account the effect of such rescinded or modified distribution on the
Exercise Price pursuant to this Section 9(d).

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         (e) Fundamental Transactions. If, at any time following the Initial
Exercise Date, (i) the Company effects any merger or consolidation of the
Company with or into another Person, (ii) the Company effects any sale of all or
substantially all of its assets in one or a series of related transactions or
(iii) there shall occur any merger of another Person into the Company whereby
the Common Stock is cancelled, converted or reclassified into or exchanged for
other securities, cash or property (in any such case, a "FUNDAMENTAL
TRANSACTION"), then, as a condition to the consummation of such Fundamental
Transaction, the Company shall (or, in the case of any Fundamental Transaction
in which the Company is not the surviving entity, the Company shall take all
reasonable steps to cause such other Person to) execute and deliver to the
Holder of this Warrant a written instrument providing that:

               (x) so long as this Warrant remains outstanding, upon the
exercise hereof at any time on or after the consummation of such Fundamental
Transaction and on such terms and subject to such conditions as shall be nearly
equivalent as may be practicable to the provisions set forth in this Warrant,
this Warrant shall be exercisable into, in lieu of Common Stock issuable upon
such exercise prior to such consummation, the securities or other property (the
"SUBSTITUTED PROPERTY") that would have been received in connection with such
Fundamental Transaction by a holder of the number of shares of Common Stock into
which this Warrant was exercisable immediately prior to such Fundamental
Transaction, assuming such holder of Common Stock:

                  (A) is not a Person with which the Company consolidated or
into which the Company merged or which merged into the Company or to which such
sale or transfer was made, as the case may be (a "CONSTITUENT PERSON"), or an
Affiliate of a Constituent Person; and

                  (B) failed to exercise such Holder's rights of election, if
any, as to the kind or amount of securities, cash and other property receivable
in connection with such Fundamental Transaction (provided, however, that if the
kind or amount of securities, cash or other property receivable in connection
with such Fundamental Transaction is not the same for each share of Common Stock
held immediately prior to such Fundamental Transaction by a Person other than a
Constituent Person or an Affiliate thereof and in respect of which such rights
of election shall not have been exercised (a "NON-ELECTING SHARE"), then, for
the purposes of this Section 9(e), the kind and amount of securities, cash and
other property receivable in connection with such Fundamental Transaction by
each Non-Electing Share shall be deemed to be the kind and amount so receivable
per share by a plurality of the Non-Electing Shares); and

               (y) the rights and obligations of the Company (or, in the event
of a transaction in which the Company is not the surviving Person, such other
Person) and the Holder in respect of Substituted Property shall be as nearly
equivalent as may be practicable to the rights and obligations of the Company
and Holder in respect of Common Stock hereunder.

            Such written instrument shall provide for adjustments which, for
events subsequent to the effective date of such written instrument, shall be as
nearly equivalent as may be practicable to the adjustments provided for in this
Section 9. The above provisions of this Section 9(e) shall similarly apply to
successive Fundamental Transactions.

         (f) Adjustment of Warrant Shares. Simultaneously with any adjustment to
the Exercise Price pursuant to paragraphs (a) through (d) of this Section 9, the
number of Warrant Shares that may be purchased upon exercise of this Warrant
shall be increased or decreased proportionately, so that after such adjustment
the aggregate Exercise Price payable hereunder for the increased or decreased
number of Warrant Shares shall be the same as the aggregate Exercise

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Price payable for the Warrant Shares immediately prior to such adjustment.

         (g) Calculations. All calculations under this Section 9 shall be made
to the nearest cent or the nearest 1/100th of a share, as applicable. The number
of shares of Common Stock outstanding at any given time shall not include shares
owned or held by or for the account of the Company, and the disposition of any
such shares shall be considered an issue or sale of Common Stock.

         (h) Adjustments. Notwithstanding any provision of this Section 9, no
adjustment of the Exercise Price shall be required if such adjustment is less
than $0.01; provided, however, that any adjustments which by reason of this
Section 9(h) are not required to be made shall be carried forward and taken into
account for purposes of any subsequent adjustment required to be made hereunder.

         (i) Notice of Adjustments. Upon the occurrence of each adjustment
pursuant to this Section 9, the Company will promptly deliver to the Holder a
certificate executed by the Company's Chief Financial Officer setting forth, in
reasonable detail, the event requiring such adjustment and the method by which
such adjustment was calculated, the adjusted Exercise Price and the adjusted
number or type of Warrant Shares or other securities issuable upon exercise of
this Warrant (as applicable). The Company will retain at its office copies of
all such certificates and cause the same to be available for inspection at said
office during normal business hours by the Holder or any prospective purchaser
of the Warrant designated by the Holder.

         (j) Notice of Corporate Events. If the Company (i) declares a dividend
or any other distribution of cash, securities or other property in respect of
its Common Stock, including, without limitation, any granting of rights or
warrants to subscribe for or purchase any capital stock of the Company or any
subsidiary of the Company, (ii) authorizes, approves, enters into any agreement
contemplating, or solicits stockholder approval for, any Fundamental Transaction
or (iii) authorizes the voluntary dissolution, liquidation or winding up of the
affairs of the Company, then the Company shall deliver to the Holder a notice
describing the material terms and conditions of such transaction at least 15
calendar days prior to the applicable record or effective date on which a Person
would need to hold Common Stock in order to participate in or vote with respect
to such transaction, and the Company will take all steps reasonably necessary in
order to ensure that the Holder is given the practical opportunity to exercise
this Warrant prior to such time so as to participate in or vote with respect to
such transaction; provided, however, that the failure to deliver such notice or
any defect therein shall not affect the validity of the corporate action
required to be described in such notice.

      10. Fractional Shares. The Company shall not be required to issue or cause
to be issued fractional Warrant Shares on the exercise of this Warrant. If any
fraction of a Warrant Share would, except for the provisions of this Section 10,
be issuable upon exercise of this Warrant, the Company shall make a cash payment
to the Holder equal to (a) such fraction multiplied by (b) the Market Price on
the Exercise Date of one full Warrant Share.

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      11. Listing on Securities Exchanges. The Company has listed, and will use
its best efforts to maintain the listing of, the Warrant Shares on Nasdaq. In
furtherance and not in limitation of any other provision of this Warrant, if the
Company at any time shall list any Common Stock on any Eligible Market other
than Nasdaq, the Company will, at its expense, simultaneously list the Warrant
Shares (and use its best efforts to maintain such listing) on such Eligible
Market, upon official notice of issuance following the exercise of this Warrant;
and the Company will so list, register and use its best efforts to maintain such
listing on any Eligible Market any Other Securities, if and at the time that any
securities of like class or similar type shall be listed on such Eligible Market
by the Company.

      12. Remedies. The Company stipulates that the remedies at law of the
Holder of this Warrant in the event of any default or threatened default by the
Company in the performance of or compliance with any of the terms of this
Warrant are not and will not be adequate, and that such terms may be
specifically enforced by a decree for the specific performance of any agreement
contained herein or by an injunction against a violation of any of the terms
hereof or otherwise.

      13. Notices. Any and all notices or other communications or deliveries
hereunder (including without limitation any Exercise Notice) shall be in writing
and shall be mailed by certified mail, return receipt requested, or by a
nationally recognized courier service or delivered (in person or by facsimile),
against receipt to the party to whom such notice or other communication is to be
given. Any notice or other communication given by means permitted by this
Section 13 shall be deemed given at the time of receipt thereof. The address for
such notices or communications shall be as set forth below:

      If to the Company:         Biopure Corporation
                                 11 Hurley Street
                                 Cambridge, MA 02141

      If to the Holder:          c/o Biopure Corporation
                                 11 Hurley Street
                                 Cambridge, MA 02141

Or such other address as is provided to such other party in accordance with this
Section 13.

      14. Warrant Agent. The Company shall serve as warrant agent under this
Warrant. Upon a prompt written notice to the Holder, the Company may appoint a
new warrant agent. Any Person into which any new warrant agent may be merged,
any Person resulting from any consolidation to which any new warrant agent shall
be a party or any Person to which any new warrant agent transfers substantially
all of its corporate trust or shareholders services business shall be a
successor warrant agent under this Warrant without any further act. Any such
successor warrant agent shall promptly cause notice of its succession as warrant
agent to be mailed (by first class mail, postage prepaid) to the Holder at the
Holder's last address as shown on the Warrant Register.

      15. Miscellaneous.

         (a) This Warrant may be assigned by the Holder. This Warrant may not be
assigned by the Company, except to a successor in the event of a Fundamental
Transaction. This Warrant shall be binding on and inure to the benefit of the
parties hereto and their respective successors

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and assigns. Subject to the preceding sentence, nothing in this Warrant shall be
construed to give to any Person other than the Company and the Holder any legal
or equitable right, remedy or cause of action under this Warrant. This Warrant
may be amended only in writing signed by the Company and the Holder and their
successors and assigns.

         (b) The Company will not, by amendment of its governing documents or
through any reorganization, transfer of assets, consolidation, merger,
dissolution, issue or sale of securities or any other voluntary action, avoid or
seek to avoid the observance or performance of any of the terms of this Warrant,
but will at all times in good faith assist in the carrying out of all such terms
and in the taking of all such action as may be necessary or appropriate in order
to protect the rights of the Holder against impairment. Without limiting the
generality of the foregoing, the Company (i) will not increase the par value of
any Warrant Shares above the amount payable therefor upon exercise thereof, and
(ii) will take all such action as may be reasonably necessary or appropriate in
order that the Company may validly and legally issue fully paid and
nonassessable Warrant Shares on the exercise of this Warrant, free from all
taxes, liens, claims and encumbrances and (iii) will not close its shareholder
books or records in any manner which interferes with the timely exercise of this
Warrant.

         (c) This Warrant shall be governed by and construed and enforced in
accordance with the laws of the State of New York. Each party hereby irrevocably
submits to the exclusive jurisdiction of the state and Federal courts sitting in
the City of New York, Borough of Manhattan, for the adjudication of any dispute
hereunder or in connection herewith or with any transaction contemplated hereby
or discussed herein, and hereby irrevocably waives, and agrees not to assert in
any suit, action or proceeding that it is not personally subject to the
jurisdiction of any such court or that such suit, action or proceeding is
improper. Each party hereby irrevocably waives personal service of process and
consents to process being served in any such suit, action or proceeding by
mailing a copy thereof via registered or certified mail or overnight delivery
(with evidence of delivery) to such party at the address in effect for notices
to it under this Warrant and agrees that such service shall constitute good and
sufficient service of process and notice thereof. Nothing contained herein shall
be deemed to limit in any way any right to serve process in any manner permitted
by law. THE PARTIES HEREBY WAIVE ALL RIGHTS TO A TRIAL BY JURY.

         (d) Neither party shall be deemed in default of any provision of this
Warrant, to the extent that performance of its obligations or attempts to cure a
breach hereof are delayed or prevented by any event reasonably beyond the
control of such party, including, without limitation, war, hostilities, acts of
terrorism, revolution, riot, civil commotion, national emergency, strike,
lockout, unavailability of supplies, epidemic, fire, flood, earthquake, force of
nature, explosion, embargo, or any other Act of God, or any law, proclamation,
regulation, ordinance, or other act or order of any court, government or
governmental agency, provided that such party gives the other party written
notice thereof promptly upon discovery thereof and uses reasonable efforts to
cure or mitigate the delay or failure to perform.

         (e) The headings herein are for convenience only, do not constitute a
part of this Warrant and shall not be deemed to limit or affect any of the
provisions hereof.

         (f) In case any one or more of the provisions of this Warrant shall be
deemed invalid or unenforceable in any respect, the validity and enforceability
of the remaining terms and provisions of this Warrant shall not in any way be
affected or impaired thereby and the parties will attempt in good faith to agree
upon a valid and enforceable provision which shall be a

                                      -10-

<PAGE>

commercially reasonable substitute therefor, and upon so agreeing, shall
incorporate such substitute provision in this Warrant.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK,
                             SIGNATURE PAGE FOLLOWS]

                                      -11-

<PAGE>

         IN WITNESS WHEREOF, the Company has caused this Warrant to be duly
executed by its authorized officer as of the date first indicated above.

                               BIOPURE CORPORATION

                               By: ___________________________________
                                   Name:
                                   Title:

                             [UNDERWRITERS WARRANT]

<PAGE>

                                   APPENDIX A

                               FORM OF ASSIGNMENT

           (to be completed and signed only upon transfer of Warrant)

         FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers
unto ________________________________________ the right represented by the
within Warrant to purchase _____________ shares of Common Stock of Biopure
Corporation to which the within warrant relates and appoints
__________________________ attorney to transfer said right on the books of
Biopure Corporation with full power of substitution in the premises.

Dated:____________                          ____________________________________
                                            (Signature must conform in all
                                            respects to name of Holder as
                                            specified on face of the Warrant)

                                            Address of Transferee:

                                            ____________________________________

                                            ____________________________________

                                            ____________________________________

In the presence of:

_____________________________________

<PAGE>

                                   APPENDIX B

                             FORM OF EXERCISE NOTICE

(To be executed by the Holder to exercise the right to purchase shares of Common
Stock under the foregoing Warrant)

To: Biopure Corporation

The undersigned is the Holder of Warrant No. [ ] (the "Warrant") issued by
Biopure Corporation, a Delaware corporation (the "Company"). Capitalized terms
used herein and not otherwise defined have the respective meanings set forth in
the Warrant.

1.    The Warrant is currently exercisable to purchase a total of _________
      Warrant Shares.

2.    The undersigned Holder hereby exercises its right to purchase _________
      Warrant Shares pursuant to the Warrant.

3.    The Holder shall pay the sum of $________ to the Company in accordance
      with the terms of the Warrant.

4.    Pursuant to this exercise, the Company shall deliver to the Holder Warrant
      Shares in accordance with the terms of the Warrant

5.    Following this exercise, the Warrant shall be exercisable to purchase a
      total of __________ Warrant Shares.

Dated: ____________                      Name of Holder:

                                         (Print) _______________________________

                                         By: ___________________________________

                                         Title: ________________________________

                                         (Signature must conform in all
                                         respects to name of Holder as specified
                                         on face of the Warrant)<PAGE>

                                                                    EXHIBIT 4.27

                                     WARRANT
                                       TO
                 PURCHASE ______ SHARES OF CLASS A COMMON STOCK
                                       OF
                               BIOPURE CORPORATION

Warrant No. ___                                         Dated: December __, 2006

      THIS CERTIFIES THAT, for value received, _______ or its assigns, (the
"HOLDER"), as registered owner of this warrant (the "WARRANT"), is entitled to
purchase and receive, in whole or in part, subject to the provisions of this
Warrant, from Biopure Corporation, a Delaware corporation (the "COMPANY"), up to
____ fully paid, validly issued and nonassessable shares of Class A common
stock, par value $.01 per share (the "COMMON STOCK"), of the Company (the
"WARRANT SHARES") at a price per share equal to $____ (the "EXERCISE PRICE")
(120% of the public offering price per unit); provided, however, that the number
and kind of securities for which this Warrant is exercisable are subject to
further adjustment in certain events, such as mergers, splits, stock dividends,
recapitalizations and the like, to prevent dilution, as set forth herein. This
Warrant shall be exercisable at any time and from time to time during the period
commencing one (1) year after (the "COMMENCEMENT DATE") the date of hereof up to
and including December __, 2011 (the "EXPIRATION DATE"), and subject to the
terms and conditions set forth herein. If the Expiration Date is a day on which
banking institutions are authorized by law to close, then this Warrant may be
exercised on the next succeeding day which is not such a day in accordance with
the terms herein. During the period beginning on the Commencement Date and
ending on the Expiration Date, the Company agrees not to take any action that
would terminate the Warrant.

      Section 1. Exercise.

            Section 1.1 Exercise Form. In order to exercise this Warrant, the
      exercise form attached hereto must be duly executed and completed and
      delivered to the Company, together with this Warrant and payment of the
      Exercise Price in cash or by certified check or official bank check for
      the Warrant Shares being purchased. If the subscription rights represented
      hereby shall not be exercised at or before 5:00 p.m., Eastern time, on the
      Expiration Date, this Warrant shall become and be void without further
      force or effect, and all rights represented hereby shall cease and expire.

            Section 1.2 Conversion Right.

               Section 1.2.1 Determination of Amount. In lieu of the payment of
      the Exercise Price in the manner required by Section 1.1, the Holder shall
      have the right (but not the obligation) to convert any exercisable but
      unexercised portion of this Warrant into Warrant Shares (the "CONVERSION
      RIGHT") as follows. Upon exercise of the Conversion Right, the Company
      shall deliver to the Holder (without payment by the Holder of any of the
      Exercise Price in cash) that number of Warrant Shares equal to the
      quotient obtained by dividing (x) the "VALUE" (as defined below), at the
      close of trading on the next to last trading day immediately preceding the
      exercise of the Conversion Right, of the portion of the Warrant being
      converted by (y) the "MARKET PRICE" (as defined below). The "VALUE" of the
      portion of the Warrant being converted shall equal the remainder derived
      from subtracting (a) the Exercise Price multiplied by the number of
      Warrant Shares underlying that portion of the Warrant being converted from
      (b) the Market Price of the Warrant Shares multiplied by the number of
      Warrant Shares underlying that portion of the Warrant being converted. As
      used in this herein, the term "MARKET PRICE" at any date shall be deemed
      to be the sum of (A) the average last reported sale price of the shares
      for the five trading days ending

<PAGE>

      on the next to last trading day immediately preceding the exercise of the
      Conversion Right as officially reported by the principal securities
      exchange on which the shares are listed or admitted to trading, or, if the
      shares are not listed or admitted to trading on any national securities
      exchange or if any such exchange on which the shares are listed is not its
      principal trading market, the average last reported sale price for such
      five trading days as furnished by the NASD through the Nasdaq Global
      Market or Nasdaq Capital Market, or, if applicable, the OTC Bulletin
      Board, or if the shares are not listed or admitted to trading on any of
      the foregoing markets, or similar organization, as determined in good
      faith by resolution of the Board of Directors of the Company, based on the
      best information available to it and (B) the intrinsic value of the
      Warrant using the share price determined in (A).

               Section 1.2.2 Mechanics of Conversion. The Conversion Right may
      be exercised by the Holder on any business day on or after the
      Commencement Date and not later than the Expiration Date by delivering the
      Warrant with a duly executed exercise form attached hereto with the
      Conversion Right section completed to the Company, exercising the
      Conversion Right and specifying the total number of Warrant Shares that
      the Holder will purchase pursuant to such Conversion Right.

            Section 1.3 Notwithstanding anything to the contrary herein, after
the sixth (6th) month anniversary of the date hereof, the Company may, by
written notice to the Holder, require that the Holder execute and deliver to the
Company an Exercise Notice exercising all of the Warrant Shares then held by
such Holder within twenty (20) Business Days of the date of the Company's
notice; provided, however, that the Company may only provide such notice if the
daily volume weighted average price per share of the Common Stock for each of
the ten (10) consecutive trading days ended immediately prior to the Company's
notice is equal to or greater than the Exercise Price multiplied by 1.5. At 5:00
P.M. New York City time on such twentieth (20th) Business Day, the portion of
this Warrant not exercised prior thereto shall be and become void and of no
value, and the Holder hereof shall have no right to purchase any additional
Warrant Shares hereunder.

      Section 2. Transfer.

            Section 2.1 General Restrictions. The registered Holder of this
      Warrant, by its acceptance hereof, agrees that, for a period commencing on
      the date hereof and ending one hundred eighty (180) days after the
      effective date of the Registration Statement, inclusive (the "LOCK-UP
      PERIOD"), it will not sell, transfer or assign or hypothecate this Warrant
      to anyone other than (i) an officer or partner of such Holder, (ii) an
      officer of either Dawson James Securities, Inc. or [_______], the
      underwriters of the public offering with respect to which this Warrant has
      been issued ("UNDERWRITERS") or an officer or partner of any selected
      dealer in connection with the Company's public offering with respect to
      which this Warrant has been issued, or (iii) any selected dealer.
      Following the Lock-Up Period, transfers to others may be made subject to
      compliance with or exemptions from applicable securities laws. In order to
      make any permitted assignment, the Holder must deliver to the Company the
      assignment form attached hereto duly executed and completed, together with
      the Warrant and payment of all transfer taxes, if any, payable in
      connection therewith. The Company shall immediately transfer this Warrant
      on the books of the Company and shall execute and deliver a new Warrant of
      like tenor to the appropriate assignee(s) expressly evidencing the right
      to purchase the aggregate number of Warrant Shares purchasable hereunder
      or such portion of such number as shall be contemplated by any such
      assignment.

            Section 2.2 Restrictions Imposed by the Act. This Warrant and the
      Warrant Shares underlying this Warrant shall not be transferred unless and
      until (i) the Company has received the opinion of counsel for the Holder
      that this Warrant or the Warrant Shares, as the case

                                      -2-

<PAGE>

      may be, may be transferred pursuant to an exemption from registration
      under the Act and applicable state law, the availability of which is
      established to the reasonable satisfaction of the Company (the Company
      hereby agreeing that an opinion of Cozen O'Connor shall be deemed
      satisfactory evidence of the availability of an exemption), or (ii) a
      registration statement relating to such Warrant or Warrant Shares, as the
      case may be, has been filed by the Company and declared effective by the
      Securities and Exchange Commission (the "COMMISSION") and compliance with
      applicable state law.

      Section 3. New Warrant to be Issued.

            Section 3.1 Partial Exercise or Transfer. Subject to the
      restrictions in Section 3 hereof, this Warrant may be exercised or
      assigned in whole or in part. In the event of the exercise or assignment
      hereof in part only, upon surrender of this Warrant for cancellation,
      together with the duly executed exercise or assignment form and funds
      sufficient to pay any Exercise Price and/or transfer tax, the Company
      shall cause to be delivered to the Holder without charge a new Warrant of
      like tenor to this Warrant in the name of the Holder evidencing the right
      of the Holder to purchase the aggregate number of Warrant Shares
      purchasable hereunder as to which this Warrant has not been exercised or
      assigned.

            Section 3.2 Lost Certificate. Upon receipt by the Company of
      evidence satisfactory to it of the loss, theft, destruction or mutilation
      of this Warrant and of reasonably satisfactory indemnification, and upon
      surrender and cancellation of the Warrant, if mutilated, the Company shall
      execute and deliver a new Warrant of like tenor and date. Any such new
      Warrant executed and delivered as a result of such loss, theft, mutilation
      or destruction shall constitute a substitute contractual obligation on the
      part of the Company.

                                      -3-

<PAGE>

Section 4. Registration Rights.

            Section 4.1 Registration. This Warrant and the Warrant Shares
issuable upon exercise of the Warrant (the Warrant and Warrant Shares
collectively referred to hereinafter as the "REGISTRABLE SECURITIES") have been
registered pursuant to the Company's Registration Statement on Form S-1 (File
No. 333-138049), as such registration statement is amended, supplemented, or
replaced (the "REGISTRATION STATEMENT"), and the Company covenants and agrees to
maintain the effectiveness of the Registration Statement until the Expiration
Date. Notwithstanding the foregoing, in the event that, prior to the Expiration
Date, the Company ceases to be eligible under the Securities Act of 1933, as
amended (the "ACT") or the rules and regulations promulgated thereunder, to
maintain a registration statement on Form S-1, or in the event that the Warrant
or the Warrant Shares cease to be eligible for inclusion in such Registration
Statement to the extent necessary to permit the Holder to exercise the Warrant
and sell the Warrant Shares without restriction under the Act, the Company will
promptly (and in any event within 10 days of the date that the Warrant or any
Warrant Shares cease to be so eligible), amend or file a new registration
statement under the Act on a form eligible for use by the Company for the
registration of such securities and use its best efforts to have such
registration statement declared effective by the Commission as soon as
practicable after such filing, which registration statement shall include such
information as may be required to permit the exercise of the Warrant and the
sale of the Warrant Shares without restriction under the Act. The Holder
acknowledges and agrees that the Warrant shall be exercisable pursuant to any
such registration statement only at such times as the registration statement is
effective or in accordance with any applicable exemption from the registration
requirements of the Act. Upon such Registration Statement being declared
effective by the Commission, the Company shall use its best efforts to cause the
Registration Statement to remain effective for a period of at least six (6)
consecutive months from the date that the Holders of the Warrant and the Warrant
Shares are covered by such Registration Statement are first given the
opportunity to sell all of such securities. During such time as the Warrant
Shares are registered pursuant to any registration statement under the Act, the
Company further covenants and agrees to make timely filings of all documents
required to be filed under the Act or the Exchange Act in order to ensure that
the registration statement, including the documents incorporated by reference
therein, if any, do not contain an untrue statement of a material fact or omit
to state any material fact required to be stated therein or necessary in order
to make the statements therein not misleading.

            Section 4.2 Expenses. The Company shall bear all fees and expenses
attendant to registering the Registrable Securities.

            Section 4.3 Exercise of Warrants. Nothing contained in this Warrant
shall be construed as requiring the Holder(s) to exercise their Warrants prior
to or after the initial filing of any registration statement or the
effectiveness thereof.

            Section 4.4 Documents to be Delivered by Holder(s). Each of the
Holder(s) participating in any of the foregoing offerings shall furnish to the
Company a completed and executed questionnaire provided by the Company
requesting information customarily sought of selling securityholders.

                                      -4-

<PAGE>

            Section 4.5 Remedies. The Company stipulates that the remedies at
law of the Holder of this Warrant in the event of any default or threatened
default by the Company in the performance of or compliance with any of the terms
of this Warrant are not and will not be adequate, and that such terms may be
specifically enforced by a decree for the specific performance of any agreement
contained herein or by an injunction restraining any breach, actual or
threatened, of the terms of this Warrant, without the necessity of showing
economic loss. The remedies provided herein shall be cumulative and in addition
to all other remedies available under this Warrant, at law or in equity, and
nothing herein shall limit the right of the Holder to pursue actual damages for
any failure by the Company to comply with the terms of the Warrant.

Section 5. Adjustments.

            Section 5.1 Adjustments to Exercise Price and Number of Securities.
The Exercise Price and the number of the Warrant Shares underlying the Warrant
shall be subject to adjustment from time to time as hereinafter set forth:

               Section 5.1.1 If after the date hereof, and subject to the
provisions of Section 5.2 below, the number of outstanding shares of Common
Stock is increased by a stock dividend payable in shares of Common Stock or by a
split-up of shares of Common Stock or other similar event, then, on the
effective date thereof, the number of shares of Common Stock underlying the
Warrant shall be increased in proportion to such increase in outstanding shares.

               Section 5.1.2 If after the date hereof, and subject to the
provisions of Section 5.2, the number of outstanding shares of Common Stock is
decreased by a consolidation, combination or reclassification of shares of
Common Stock or other similar event, then, on the effective date thereof, the
number of shares of Common Stock underlying the Warrant shall be decreased in
proportion to such decrease in outstanding shares.

               Section 5.1.3 In case of any reclassification or reorganization
of the outstanding shares of Common Stock other than a change covered by Section
5.1.1 or 5.1.2 hereof or that solely affects the par value of such shares of
Common Stock, or in the case of any merger or consolidation of the Company with
or into another corporation (other than a consolidation or merger in which the
Company is the continuing corporation and that does not result in any
reclassification or reorganization of the outstanding shares of Common Stock),
or in the case of any sale or conveyance to another corporation or entity of the
property of the Company as an entirety or substantially as an entirety in
connection with which the Company is dissolved, the Holder of this Warrant shall
have the right thereafter (until the expiration of the right of exercise of this
Warrant) to receive upon the exercise hereof, for the same aggregate Exercise
Price payable hereunder immediately prior to such event, the kind and amount of
shares of stock or other securities or property (including cash) receivable upon
such reclassification, reorganization, merger or consolidation, or upon a
dissolution following any such sale or transfer, by a Holder of the number of
shares of Common Stock of the Company obtainable upon exercise of this Warrant
immediately prior to such event; and if any reclassification also results in a
change in shares of Common Stock covered by Section 5.1.1 or 5.1.2, then such
adjustment shall be made pursuant to Sections 5.1.1, 5.1.2 and this Section
5.1.3. The provisions of this Section 5.1.3 shall similarly apply to successive
reclassifications, reorganizations, mergers or consolidations, sales or other
transfers.

               Section 5.1.4 This form of Warrant need not be changed because of
any change pursuant to this Section, and Warrants issued after such change may
state the same Exercise Price and the same number of Warrant Shares as are
stated in the Warrant initially issued pursuant to this Agreement. The
acceptance by any Holder of the issuance of new Warrant

                                      -5-

<PAGE>

reflecting a required or permissive change shall not be deemed to waive any
rights to an adjustment occurring after the Commencement Date or the computation
thereof.

               Section 5.1.5 In case of any consolidation of the Company with,
or merger of the Company with, or merger of the Company into, another
corporation (other than a consolidation or merger which does not result in any
reclassification or change of the outstanding Common Stock), the corporation
formed by such consolidation or merger shall execute and deliver to the Holder a
replacement Warrant providing that the Holder of each Warrant then outstanding
or to be outstanding shall have the right thereafter (until the stated
expiration of such Warrant) to receive, upon exercise of such Warrant the kind
and amount of shares of stock and other securities and property receivable upon
such consolidation or merger, by a holder of the number of shares of Common
Stock of the Company for which such Warrant might have been exercised
immediately prior to such consolidation, merger, sale or transfer. Such
replacement Warrant shall provide for adjustments which shall be identical to
the adjustments provided in Section 5. The above provision of this Section shall
similarly apply to successive consolidations or mergers.

            Section 5.2 Elimination of Fractional Interests. The Company shall
not be required to issue certificates representing fractions of shares of Common
Stock or Warrants upon the exercise of the Warrant, nor shall it be required to
issue scrip or pay cash in lieu of any fractional interests, it being the intent
of the parties that all fractional interests shall be eliminated by rounding any
fraction down to the nearest whole number of Warrants, shares of Common Stock or
other securities, properties or rights.

Section 6. Reservation and Listing.

            The Company shall at all times reserve and keep available out of its
authorized shares of Common Stock, solely for the purpose of issuance upon
exercise of the Warrant such number of shares of Common Stock or other
securities, properties or rights as shall be issuable upon the exercise thereof.
The Company covenants and agrees that, upon exercise of the Warrant and payment
of the Exercise Price therefor, all shares of Common Stock and other securities
issuable upon such exercise shall be duly and validly issued, fully paid and
non-assessable and not subject to preemptive rights of any stockholder. As long
as the Warrant shall be outstanding, the Company shall use its best efforts to
cause all Warrant Shares issuable upon exercise of the Warrant to be listed
(subject to official notice of issuance) on all securities exchanges (or, if
applicable on the Nasdaq National Market, Capital Market, OTC Bulletin Board or
any successor trading market) on which the Common Stock or the Public Warrants
issued to the public in connection herewith may then be listed and/or quoted.

Section 7. Certain Notice Requirements.

            Section 7.1 Holder's Right to Receive Notice. Nothing herein shall
be construed as conferring upon the Holder the right to vote or consent as a
stockholder for the election of directors or any other matter, or as having any
rights whatsoever as a stockholder of the Company. If, however, at any time
prior to the expiration of the Warrant and its exercise, any of the events
described in Section 7.2 shall occur, then, in one or more of said events, the
Company shall give written notice of such event at least fifteen (15) days prior
to the date fixed as a record date or the date of closing the transfer books for
the determination of the stockholders entitled to such dividend, distribution,
conversion or exchange of securities or subscription rights, or entitled to vote
on such proposed dissolution, liquidation, winding up or sale. Such notice shall
specify such record date or the date of the closing of the transfer books, as
the case may be. Notwithstanding the foregoing, the Company shall deliver to the
Holder a copy of each notice

                                      -6-

<PAGE>

given to the other stockholders of the Company at the same time and in the same
manner that such notice is given to the stockholders.

            Section 7.2 Enumerated Events. The Company shall be required to give
the notice described in this Section 7 upon one or more of the following events:
(i) if the Company shall take a record of the holders of its shares of Common
Stock for the purpose of entitling them to receive a dividend or distribution
payable otherwise than in cash, or a cash dividend or distribution payable
otherwise than out of retained earnings, as indicated by the accounting
treatment of such dividend or distribution on the books of the Company, or (ii)
the Company shall offer to all the holders of its Common Stock any additional
shares of capital stock of the Company or securities convertible into or
exchangeable for shares of capital stock of the Company, or any option, right or
warrant to subscribe therefor, or (iii) a dissolution, liquidation or winding up
of the Company (other than in connection with a consolidation or merger) or a
sale of all or substantially all of its property, assets and business shall be
proposed by the Company.

            Section 7.3 Change in Exercise Price. The Company shall, promptly
after an event requiring a change in the Exercise Price pursuant to Section 7
hereof, send notice to the Holder of such event and change (the "PRICE NOTICE").
The Price Notice shall describe the event causing the change and the method of
calculating same and shall be certified as being true and accurate by the
Company's President and Chief Financial Officer.

            Section 7.4 Transmittal of Notices. All notices, requests, consents
and other communications under this Warrant shall be in writing and shall be
deemed to have been duly made on the date of delivery if delivered personally or
sent by overnight courier, with acknowledgement of receipt to the party to which
notice is given, or on the fifth day after mailing if mailed to the party to
whom notice is to be given, by registered or certified mail, return receipt
requested, postage prepaid and properly addressed as follows: (i) if to the
registered Holder of the Warrant, to the address of such Holder as shown on the
books of the Company, or (ii) if to the Company, to its principal executive
office.

Section 8. Miscellaneous.

            Section 8.1 Amendments. The Company and the Underwriters may from
time to time supplement or amend this Warrant without the approval of any of the
Holders in order to cure any ambiguity, to correct or supplement any provision
contained herein which may be defective or inconsistent with any other
provisions herein, or to make any other provisions in regard to matters or
questions arising hereunder which the Company and the Underwriters may deem
necessary or desirable and which the Company and the Underwriters deem shall not
adversely affect the interest of the Holders. All other modifications or
amendments shall require the written consent of the party against whom
enforcement of the modification or amendment is sought.

            Section 8.2 Headings. The headings contained herein are for the sole
purpose of convenience of reference, and shall not in any way limit or affect
the meaning or interpretation of any of the terms or provisions of this Warrant.

            Section 8.3 Entire Agreement. This Warrant (together with the other
agreements and documents being delivered pursuant to or in connection with this
Warrant) constitutes the entire agreement of the parties hereto with respect to
the subject matter hereof, and supersedes all prior agreements and
understandings of the parties, oral and written, with respect to the subject
matter hereof.

                                      -7-

<PAGE>

            Section 8.4 Binding Effect. This Warrant shall inure solely to the
benefit of and shall be binding upon, the Holder and the Company and their
respective successors, legal representatives and assigns, and no other person
shall have or be construed to have any legal or equitable right, remedy or claim
under or in respect of or by virtue of this Warrant or any provisions herein
contained.

            Section 8.5 Governing Law; Submission to Jurisdiction. This Warrant
shall be governed by and construed and enforced in accordance with the laws of
the State of New York, without giving effect to conflict of laws. The Company
hereby agrees that any action, proceeding or claim against it arising out of, or
relating in any way to this Warrant shall be brought and enforced in the courts
of the State of New York or of the United States of America for the Southern
District of New York, and irrevocably submits to such jurisdiction, which
jurisdiction shall be exclusive. The Company hereby waives any objection to such
exclusive jurisdiction and that such courts represent an inconvenient forum. Any
process or summons to be served upon the Company may be served by transmitting a
copy thereof by registered or certified mail, return receipt requested, postage
prepaid, addressed to BIOPURE CORPORATION, 11 HURLEY STREET, CAMBRIDGE, MA
02141, ATTN: JANE KOBER, ESQ. Such mailing shall be deemed personal service and
shall be legal and binding upon the Company in any action, proceeding or claim.
The Company and the Holder, by acceptance hereof, agree that the prevailing
party(ies) in any such action shall be entitled to recover from the other
party(ies) all of its reasonable attorneys' fees and expenses relating to such
action or proceeding and/or incurred in connection with the preparation
therefor.

            Section 8.6 Waiver, Etc. The failure of the Company or the Holder to
at any time enforce any of the provisions of this Warrant shall not be deemed or
construed to be a waiver of any such provision, nor to in any way affect the
validity of this Warrant or any provision hereof or the right of the Company or
any Holder to thereafter enforce each and every provision of this Warrant. No
waiver of any breach, non-compliance or non-fulfillment of any of the provisions
of this Warrant shall be effective unless set forth in a written instrument
executed by the party or parties against whom or which enforcement of such
waiver is sought; and no waiver of any such breach, non-compliance or
non-fulfillment shall be construed or deemed to be a waiver of any other or
subsequent breach, non-compliance or non-fulfillment.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK,
                             SIGNATURE PAGE FOLLOWS]

                                      -8-

<PAGE>

            IN WITNESS WHEREOF, the Company has caused this Warrant to be duly
executed by its authorized officer as of the date first indicated above.

                               BIOPURE CORPORATION

                               By:____________________________
                                  Name:
                                  Title:

                             [UNDERWRITERS WARRANT]

<PAGE>

FORM TO BE USED TO EXERCISE WARRANT:

Biopure Corporation

Date:_________________, 200__

            The undersigned hereby elects irrevocably to exercise the within
Warrant and to purchase ____ Biopure Corporation and hereby makes payment of
$____________ (at the rate of $_________ per Share) in payment of the Exercise
Price pursuant thereto. Please issue the Share as to which this Warrant is
exercised in accordance with the instructions given below.

or

            The undersigned hereby elects irrevocably to exercise the within
Warrant and to purchase _________ Biopure Corporation by surrender of the
unexercised portion of the within Warrant (with a "Value" of $_______ based on a
"Market Price" of $__________.) Please issue the Warrant Shares as to which this
Warrant is exercised in accordance with the instructions given below.

                                    _________________________________
                                    Signature

            NOTICE: THE SIGNATURE TO THIS FORM MUST CORRESPOND WITH THE NAME AS
WRITTEN UPON THE FACE OF THE WITHIN WARRANT IN EVERY PARTICULAR WITHOUT
ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATSOEVER.

                   INSTRUCTIONS FOR REGISTRATION OF SECURITIES

Name ________________________________________________________
                       (Print in Block Letters)

Address ________________________________________________________

                                      -10-

<PAGE>

Form to be used to assign Warrant:

                                   ASSIGNMENT

            (To be executed by the registered Holder to effect a transfer of the
within Warrant):

            FOR VALUE RECEIVED,__________________________________ does hereby
sell, assign and transfer unto _______________________ the right to purchase
_______________________ of Biopure Corporation ("Company") evidenced by the
within Warrant and does hereby authorize the Company to transfer such right on
the books of the Company.

Dated: ___________________, 200_

                                    _______________________________
                                    Signature

________________________________
Signature Guaranteed

            NOTICE: THE SIGNATURE TO THIS FORM MUST CORRESPOND WITH THE NAME AS
WRITTEN UPON THE FACE OF THE WITHIN WARRANT IN EVERY PARTICULAR WITHOUT
ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATSOEVER, AND MUST BE GUARANTEED BY A
BANK, OTHER THAN A SAVINGS BANK, OR BY A TRUST COMPANY OR BY A FIRM HAVING
MEMBERSHIP ON A REGISTERED NATIONAL SECURITIES EXCHANGE.

                                      -11-

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