EXHIBIT 4.7

                                WARRANT AGREEMENT

                     THIS  WARRANT  AGREEMENT  (this  "Agreement"),  dated as of
March  23,  1999  is by  and  between  HEMASURE  INC.,  a  Delaware  corporation
("HemaSure"), and SEPRACOR INC., a Delaware corporation (the "Holder").


                              W I T N E S S E T H:

                     WHEREAS,  pursuant to a  Securities  Purchase  Agreement of
even date  herewith (the  "Securities  Purchase  Agreement")  by and between the
parties hereto,  the Company (i) issued to the Holder 1,333,334 shares of common
stock,  par value $.01 per share  ("Common  Stock"),  of the  Company,  and (ii)
agreed to grant  warrants  (individually  a  "Warrant,"  and  collectively,  the
"Warrants")  to  purchase  667,000  shares of Common  Stock,  upon the terms and
conditions as set forth below.

                     NOW, THEREFORE, in consideration of these premises, and for
other good and valuable  consideration,  the receipt and sufficiency of which is
hereby acknowledged, the parties hereto agree as follows:

                     1.  Grant.  The  Holder  is  hereby  granted  the  right to
purchase 667,000 shares of Common Stock, at an exercise price of $1.50 per share
(the "Exercise Price") of Common Stock, at any time prior to 5:00 p.m., New York
City time on March 22,  2004,  subject  to  the  terms  and  conditions  of this
Agreement.

                     2.  Warrant  Certificate.   The  warrant  certificate  (the
"Warrant  Certificate")  to be delivered  pursuant to this Agreement shall be in
the form set forth in Annex I attached hereto, and made a part hereof, with such
appropriate  insertions,  omissions,  substitutions,  and  other  variations  as
required or permitted by this Agreement.

                     3. Exercise of Warrants.  The Warrants are  exercisable  at
the aggregate Exercise Price for the number of Warrants so exercised at any time
prior to 5:00 p.m. New York City time on March 22, 2004,  subject to  adjustment
as provided in Section 8 hereof.  Payment of such Exercise  Price shall be made,
at the option of the Holder  specified  in its notice of  exercise,  (i) by wire
transfer  or by  certified  or official  bank check  payable to the order of the
Company in immediately  available  funds in lawful money of the United States of
America;  or (ii) by reducing the number of shares of Common  Stock  issuable to
the Holder by a number of shares of Common  Stock that have a value equal to the
Exercise Price which  otherwise would have been paid. For purposes  hereof,  the
value of a share of Common Stock (the "Share  Value") shall be the last reported
sale  price  of the  Common  Stock  on the  OTC  Bulletin  Board,  or any  other
interdealer  quotation  system  on  which  the  Common  Stock  is  included  for
quotation, or, if none, the fair

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market value of such shares as  reasonably  determined by the Board of Directors
of the Company. Upon surrender of a Warrant Certificate with the annexed Form of
Election to Purchase duly executed,  together with payment of the Exercise Price
for the shares of Common Stock purchased, if applicable, at HemaSure's principal
offices located at 140 Locke Drive,  Marlborough,  MA 01752, the Holder shall be
entitled to receive a certificate or certificates for the shares of Common Stock
so purchased.  The purchase  rights  represented by the Warrant  Certificate are
exercisable at the option of the Holder thereof, in whole or in part (but not as
to fractional  shares of the Common Stock  underlying the  Warrants),  but in no
event for less than 25,000  shares at any one time.  In the case of the purchase
of less than all the  shares  of  Common  Stock  purchasable  under any  Warrant
Certificate,  HemaSure shall cancel said Warrant  Certificate upon the surrender
thereof and shall  execute and deliver a new Warrant  Certificate  of like tenor
for the balance of the shares of Common Stock purchasable thereunder.

                     4. Mandatory Exercise of Warrants.  The Company may require
the  Investor  to  exercise  the  purchase  rights  represented  by the  Warrant
Certificate,  in whole, at any time from and after the date on which the Company
consummates a transaction whereby a third party provides equity financing to the
Company in the principal amount of Five Million Dollars ($5,000,000) or more and
the closing price of the Company's  Common Stock as reported on the OTC Bulletin
Board, or any other interdealer  quotation system or stock market or exchange on
which the Common Stock is quoted or listed,  is greater than $3.00 per share for
15 consecutive trading days.

                     5.  Issuance  of  Certificates.  Upon the  exercise  of the
Warrants,  the  issuance  of  certificates  for shares of Common  Stock or other
securities,  properties  or  rights  underlying  such  Warrants  shall  be  made
forthwith  (and in any event within ten (10) business days  thereafter)  without
charge to the Holder including, without limitation, any tax which may be payable
in respect of the issuance thereof, and such certificates shall be issued in the
name of, or in such names as may be directed by, the Holder  thereof;  provided,
however, that HemaSure 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 such
certificates in a name other than that of the Holder,  and HemaSure shall not be
required  to issue or deliver  such  certificates  unless or until the person or
persons  requesting the issuance  thereof shall have paid to HemaSure the amount
of such tax or shall have  established to the satisfaction of HemaSure that such
tax has been paid.

                     The Warrant  Certificate and the certificates  representing
the Shares  shall be executed  on behalf of HemaSure by the manual or  facsimile
signature  of the  then  present  Chairman  or Vice  Chairman  of the  Board  of
Directors or President or Chief Executive  Officer or Vice President of HemaSure
under its  corporate  seal  reproduced  thereon,  attested  to by the  manual or
facsimile  signature  of the then present  Secretary  or Assistant  Secretary of
HemaSure.  The  Warrant  Certificate  shall be dated  the date of  execution  by
HemaSure upon initial issuance, division, exchange, substitution or transfer.


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                     6.  Restriction on Transfer of Warrants.  The Holder of the
Warrant Certificate, by its acceptance thereof, covenants and agrees:

                      (i) that the  Warrants  and the  shares  of  Common  Stock
           issuable  on  exercise  of the  Warrants  (the  "Shares")  are  being
           acquired  as an  investment  and not with a view to the  distribution
           thereof;

                     (ii) that it understands  that neither the Warrants nor the
           Shares have been  registered  under the  Securities  Act of 1933,  as
           amended (the "Securities Act"), in reliance on an exemption therefrom
           for transactions not involving any public offering,  and that neither
           the Warrants nor the Shares have been approved or  disapproved by the
           United  States  Securities  and Exchange  Commission  or by any other
           Federal or state agency;

                     (iii) it  understands  that  neither the  Warrants  nor the
           Shares can be sold,  transferred  or assigned  unless  registered  by
           HemaSure  pursuant to the  Securities  Act and any  applicable  state
           securities laws, or unless an exemption therefrom is available,  and,
           accordingly,  it may not be possible for the undersigned to liquidate
           its  investment in the Warrants and the Shares,  and it agrees not to
           sell, assign or otherwise  transfer or dispose of the Warrants or the
           Shares unless such Warrants or Shares,  as  applicable,  have been so
           registered or an exemption from registration is available;

                     (iv) the Holder  hereby  acknowledges  that all  documents,
           records and books  pertaining to  HemaSure's  business have been made
           available to the Holder and the Holder's  attorney and/or  accountant
           and/or  representative.  The  Holder  has had an  opportunity  to ask
           questions and receive  answers from HemaSure  concerning the business
           and assets of HemaSure and all such  questions  have been answered to
           the full satisfaction of the Holder; and

                      (v) it is an accredited investor,  as that term is defined
           in Regulation D under the Securities Act.

                     7. Securities Act of 1933; Legends.  Upon exercise, in part
or in whole, of the Warrants,  certificates  representing the Shares  underlying
the  Warrant  and any of the other  securities  issuable  upon  exercise  of the
Warrant (the  "Warrant  Shares")  shall bear the  following  legend only if such
Warrant  Shares are not then  registered  pursuant to an effective  registration
statement under the Act:

                     The  securities  represented by this  certificate  have not
                     been  registered  under  the  Securities  Act of  1933,  as
                     amended (the "Act"),  and may not be offered or sold except
                     pursuant to (i) an effective  registration  statement under
                     the Act, (ii) to the extent applicable,  Rule 144 under the
                     Act (or any  similar  rule under such Act  relating  to the
                     disposition of securities), or (iii) an opinion of counsel,
                     if such opinion shall be reasonably satisfactory to counsel
                     to the

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                     issuer,  that an exemption from registration under such Act
                     is available.

                     8. Subdivision and  Combination.  In case HemaSure shall at
any time  subdivide  or combine  the  outstanding  shares of Common  Stock,  the
Exercise  Price shall  forthwith  be  proportionately  decreased  in the case of
subdivision  or increased in the case of  combination,  and the number of shares
subject to the Warrant shall be  proportionally  increased or decreased,  as the
case may be.

                     9. Merger or Consolidation. In case of any consolidation of
HemaSure with, or merger of HemaSure  with, or merger of HemaSure 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
supplemental warrant agreement having terms as nearly  substantively  equivalent
as practical to the terms hereof, providing that the Holder of each Warrant then
outstanding  or to be  outstanding  shall have the right  thereafter  (until the
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 the Holder of the number of shares of Common
Stock of HemaSure for which such warrant might have been  exercised  immediately
prior to such consolidation,  merger,  sale or transfer.  The above provision of
this subsection shall similarly apply to successive consolidations or mergers.

                     10. Exchange and Replacement of Warrant Certificates.  Each
Warrant Certificate is exchangeable without expense,  upon the surrender thereof
by the Holder at the principal  executive office of HemaSure,  for a new Warrant
Certificate  of like tenor and date  representing  in the aggregate the right to
purchase  the same number of Warrant  Shares in such  denominations  as shall be
designated by the Holder thereof at the time of such surrender.

                     Upon   receipt   by   HemaSure   of   evidence   reasonably
satisfactory to it of the loss, theft,  destruction or mutilation of any Warrant
Certificate,  and,  in case of  loss,  theft  or  destruction,  of an  indemnity
agreement reasonably  satisfactory to it, and upon surrender and cancellation of
the  Warrants,  if  mutilated,  HemaSure  will make and  deliver  a new  Warrant
Certificate of like tenor, in lieu thereof.

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

                     12. Reservation of Securities.  HemaSure shall at all times
reserve and keep available out of its authorized shares of Common Stock,  solely
for the purpose of issuance  upon the exercise of the  Warrants,  such number of
shares of Common  Stock or other  securities,  properties  or rights as shall be
issuable upon the exercise thereof.

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                     13.  Notices  to the  Holder.  Nothing  contained  in  this
Agreement  shall be construed as conferring upon the Holder the right to vote or
to consent or to receive  notice as a stockholder  in respect of any meetings of
stockholders for the election of directors or any other matter, or as having any
rights whatsoever as a stockholder of HemaSure.  If, however,  at any time prior
to the  expiration  of the Warrants  and their  exercise,  any of the  following
events shall occur:

                               (a)  HemaSure  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 current or retained earnings,
                     as indicated by the  accounting  treatment of such dividend
                     or distribution on the books of HemaSure;

                               (b) HemaSure shall offer to all of the holders of
                     its Common Stock any additional  shares of capital stock of
                     HemaSure or securities convertible into or exchangeable for
                     shares of capital stock of HemaSure,  or any option,  right
                     or warrant to subscribe therefor; or

                               (c) a  dissolution,  liquidation or winding up of
                     HemaSure (other than in connection with a consolidation  or
                     merger)  or a  sale  of  all  or  substantially  all of its
                     property,  assets  and  business  as an  entirety  shall be
                     proposed;

then, in any one or more of said events,  HemaSure  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,   convertible   or
exchangeable  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 closing the transfer  books, as the case may be.
Failure to give such notice or any defect  therein shall not affect the validity
of any action taken in connection  with the  declaration  or payment of any such
dividend,  or the issuance of any  convertible or  exchangeable  securities,  or
subscription  rights,   options  or  warrants,   or  any  proposed  dissolution,
liquidation, winding up or sale.

                     14.  Notices.  All  notices,  requests,  consents and other
communications  hereunder  shall be in writing  and shall be deemed to have been
duly made and sent when  delivered,  or mailed by registered or certified  mail,
return receipt requested:

                          (a) If to the Holder,  to the address of the Holder as
                     shown on the books of HemaSure; or

                          (b)  If to  HemaSure,  to the  address  set  forth  in
                     Section 3 hereof or to such other  address as HemaSure  may
                     designate by notice to the Holder.


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                     15.  Successors.  All the covenants and  provisions of this
Agreement shall be binding upon and inure to the benefit of HemaSure, the Holder
and their respective successors and assigns hereunder.

                     16.  Termination.  This  Agreement  shall  terminate in its
entirety at 5:00 p.m., New York City time, on March 22, 2004.

                     17. Entire Agreement; Modification. This Agreement contains
the entire understanding  between the parties hereto with respect to the subject
matter hereof and may not be modified or amended except by a writing duly signed
by the party  against  whom  enforcement  of the  modification  or  amendment is
sought.

                     18. Severability.  If any provision of this Agreement shall
be held to be invalid or  unenforceable,  such  invalidity  or  unenforceability
shall not affect any other provision of this Agreement.

                     19. Captions.  The caption headings of the Sections of this
Agreement are for convenience of reference only and are not intended, nor should
they be construed as, a part of this Agreement and shall be given no substantive
effect.

                     20. Benefits of this  Agreement.  Nothing in this Agreement
shall be construed to give to any person or  corporation  other than HemaSure or
the Holder any legal or equitable right, remedy or claim under this Agreement.

                     21.  Governing Law. This Agreement  shall be deemed to have
been  made in the  State of New York and the  validity  of this  Agreement,  the
construction,  interpretation  and  enforcement  thereof,  and the rights of the
parties  thereto  shall be  determined  under,  governed  by, and  construed  in
accordance  with the internal laws of the State of New York,  without  regard to
principles of conflicts of law.

                     22. Arbitration.  Any dispute or controversy arising under,
out of, in connection with, or in relation to this Agreement shall be determined
and  settled  by  arbitration  in New York by a panel of three  (3)  members  in
accordance with the commercial  rules of the American  Arbitration  Association.
Any award rendered therein shall be final and binding upon the parties and their
legal representatives, successors and assigns and judgment may be entered in any
court having jurisdiction thereof.

                     23.  Counterparts.  This  Agreement  may be executed in any
number of counterparts and each of such  counterparts  shall for all purposes be
deemed to be an original,  and such counterparts  shall together  constitute but
one and the same  instrument.  Photocopies  or facsimiles of executed  copies of
this Agreement may be treated as originals.


                         (Signatures on Following Page)

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                     IN WITNESS  WHEREOF,  the  parties  hereto have caused this
Agreement to be duly executed, as of the day and year first above written.


                               HEMASURE INC.


                               By:  /s/ James B. Murphy
                                    ------------------------------------
                                    Name:  James B. Murphy
                                    Title: Senior Vice President of Finance
                                           and Administration


                               SEPRACOR INC.


                               By:  /s/ Robert Scumaci
                                    -------------------------------
                                    Name:  Robert Scumaci
                                    Title: Senior Vice President of Finance
                                           and Adminstration

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