SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                ----------------

                                  SCHEDULE 13G
                                 (Rule 13d-102)
                                ----------------

    INFORMATION TO BE INCLUDED IN STATEMENTS PURSUANT TO RULES 13d-1(b),(c)
             AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                         (Amendment No. _____________)*


                            DUSA PHARMACEUTICALS INC
                                (Name of Issuer)

                          Common Stock, $.01 par value
                         (Title of Class of Securities)

                                    266898105
                                 (CUSIP Number)

                                February 15, 2001
             (Date of Event Which Requires Filing of this Statement)


     Check the  appropriate  box to  designate  the rule  pursuant to which this
     Schedule is filed:
     [ ] Rule 13d-1(b)
     [X] Rule 13d-1(c)
     [ ] Rule 13d-1(d)

-----------

     * The  remainder  of this cover  page  shall be filled out for a  reporting
person's  initial  filing on this  form with  respect  to the  subject  class of
securities,  and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

     The  information  required in the remainder of this cover page shall not be
deemed to be "filed"  for the purpose of Section 18 of the  Securities  Exchange
Act of 1934 ("Act") or otherwise  subject to the  liabilities of that section of
the Act but shall be subject to all other  provisions of the Act  (however,  see
the Notes).





Schedule 13G                                                     PAGE 2 OF 14

CUSIP No. 266898105
-----------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               CLSP, L.P.
-----------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [x]
                                                                    (b)  [ ]
-----------------------------------------------------------------------------
     (3)  SEC USE ONLY

-----------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
                                    Delaware
-----------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    754,000
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    754,000
-----------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
                    754,000
-----------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
-----------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
                    5.5%
-----------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
                    PN
-----------------------------------------------------------------------------





Schedule 13G                                                     PAGE 3 OF 14

CUSIP No. 266898105
-----------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               CLSP II, L.P.
-----------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [x]
                                                                    (b)  [ ]
-----------------------------------------------------------------------------
     (3)  SEC USE ONLY

-----------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
                                    Delaware
-----------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    89,600
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    89,600
-----------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
                    89,600
-----------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
-----------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
                    0.7%
-----------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
                    PN
-----------------------------------------------------------------------------





Schedule 13G                                                     PAGE 4 OF 14

CUSIP No. 266898105
-----------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               CLSP/SBS I, L.P.
-----------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [x]
                                                                    (b)  [ ]
-----------------------------------------------------------------------------
     (3)  SEC USE ONLY

-----------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
                                    Delaware
-----------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    214,400
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    214,400
-----------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
                    214,400
-----------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
-----------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
                    1.6%
-----------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
                    PN
-----------------------------------------------------------------------------





Schedule 13G                                                     PAGE 5 OF 14

CUSIP No. 266898105
-----------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               CLSP/SBS II, L.P.
-----------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [x]
                                                                    (b)  [ ]
-----------------------------------------------------------------------------
     (3)  SEC USE ONLY

-----------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
                                    Delaware
-----------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    106,000
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    106,000
-----------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
                    106,000
-----------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
-----------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
                    0.8%
-----------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
                    PN
-----------------------------------------------------------------------------





Schedule 13G                                                     PAGE 6 OF 14

CUSIP No. 266898105
-----------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Cooper Hill Partners, L.P.
-----------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [x]
                                                                    (b)  [ ]
-----------------------------------------------------------------------------
     (3)  SEC USE ONLY

-----------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
                                    Delaware
-----------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    196,300
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    196,300
-----------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
                    196,300
-----------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
-----------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
                    1.4%
-----------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
                    PN
-----------------------------------------------------------------------------





Schedule 13G                                                     PAGE 7 OF 14

CUSIP No. 266898105
-----------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Cooper Hill Partners, LLC
-----------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [x]
                                                                    (b)  [ ]
-----------------------------------------------------------------------------
     (3)  SEC USE ONLY

-----------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
                                    Delaware
-----------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,164,000
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    1,164,000
-----------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
                    1,164,000
-----------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
-----------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
                    8.5%
    (12)  TYPE OF REPORTING PERSON
                    OO
-----------------------------------------------------------------------------





Schedule 13G                                                     PAGE 8 OF 14

CUSIP No. 266898105
-----------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
               Jeffrey Casdin
-----------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                    (a)  [x]
                                                                    (b)  [ ]
-----------------------------------------------------------------------------
     (3)  SEC USE ONLY

-----------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
                                  United States
-----------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         ______________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,360,300
OWNED BY       ______________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      ______________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    1,360,300
-----------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
                    1,360,300
-----------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES                             [ ]
-----------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
                    9.9%
-----------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON
                    IN
-----------------------------------------------------------------------------





Schedule 13G                                                     PAGE 9 OF 14

ITEM 1(a).  NAME OF ISSUER:
             DUSA PHARMACEUTICALS INC

ITEM 1(b).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:
             25 Upton Drive, Wilmington, MA  01887

ITEM 2(a).  NAME OF PERSON FILING:

     This statement is filed by:
          (i) CLSP, L.P. ("CLSP"),
              a Delaware limited partnership, with respect to the Securities
              owned by it;
         (ii) CLSP II, L.P. ("CLSP II") a Delaware limited
              partnership, with respect to the Securities owned by it;
         (iii) CLSP/SBS I, L.P. ("CLSP/SBS I") a Delaware
              limited partnership, with respect to the Securities
              owned by it;
         (iv) CLSP/SBS II, L.P. ("CLSP/SBS II") a Delaware
              limited partnership, with respect to the Securities
              owned by it;
          (v) Cooper Hill  Partners,  LLC ("Cooper,  LLC "), a Delaware  limited
              liability  company and the sole general  partner of CLSP, CLSP II,
              CLSP/SBS I AND CLSP/SBS II with respect to the Securities owned by
              CLSP, CLSP II, CLSP/SBS I AND CLSP/SBS II;
         (vi) Cooper Hill Partners, L.P., a Delaware limited partnership
              with respect to the Securities held for CLSP Overseas, Ltd.
              ("CLSP Overseas"), [a Cayman Islands exempted company]; and
        (vii) Jeffrey  Casdin a citizen of the United  States,  and the Managing
              Member of Casdin Capital,  LLC, the general partner of Cooper Hill
              Partners, L.P. and the managing member of Cooper LLC, with respect
              to Securities subject to the control of Cooper LLC and Cooper Hill
              Partners, LP.

              The foregoing  persons (other than CLSP Overseas) are  hereinafter
              sometimes collectively referred to as the "Reporting Persons." Any
              disclosures   herein  with  respect  to  persons  other  than  the
              Reporting  Persons are made on information and belief after making
              inquiry to the appropriate party.





Schedule 13G                                                  PAGE 10 OF 14

ITEM 2(b).  ADDRESS OF PRINCIPAL OFFICE OR, IF NONE, RESIDENCE:
            The business  address of each of the  Reporting  Persons is 230 Park
Avenue,  New York, New York 10169.  The business address of CLSP Overseas is c/o
Goldman Sachs (Cayman) Trust,  Limited P.O. Box 896 G.T. Harbour Centre,  Second
Floor North Church Street George Town, Grand Cayman Cayman Islands, B.W.I.

ITEM 2(c).  CITIZENSHIP:
             Cooper LLC is a Delaware limited  liability  company and CLSP, CLSP
II,  CLSP/SBS I, CLSP/SBS II and Cooper Hill Partners,  L.P. are each a Delaware
limited partnership. CLSP Overseas is a Cayman Islands exempted company. Jeffrey
Casdin is a citizen of the United States.

ITEM 2(d).  TITLE OF CLASS OF SECURITIES: Common Stock, $.01 par value

ITEM 2(e).  CUSIP NUMBER:                 266898105

ITEM 3. IF THIS  STATEMENT  IS FILED  PURSUANT  TO  13d-1(b) OR 13d-2(b) OR (c),
CHECK WHETHER THE PERSON FILING IS A:

          (a) [ ]   Broker or dealer registered under Section 15 of the
                    Act

          (b) [ ]   Bank as defined in Section 3(a)(6) of the Act

          (c) [ ]   Insurance Company as defined in Section 3(a)(19) of
                    the Act

          (d) [ ]   Investment Company registered under Section 8 of the
                    Investment Company Act of 1940

          (e) [ ]   Investment Adviser registered under Section 203 of the
                    Investment Advisers Act of 1940: see Rule 13d-
                    1(b)(1)(ii)(E)

          (f) [ ]   Employee Benefit Plan,  Pension Fund which is subject to
                    the provisions of the Employee  Retirement  Income  Security
                    Act of 1974 or Endowment Fund; see Rule 13d-1(b)(1)(ii)(F)

          (g) [ ]   Parent Holding Company, in accordance with Rule 13d-
                    1(b)(ii)(G);

          (h) [ ]   Savings Associations as defined in Section 3(b) of the
                    Federal Deposit Insurance Act;

          (i) [ ]   Church Plan that is excluded  from the  definition of an
                    investment  company under Section 3(c)(14) of the Investment
                    Company Act of 1940;





Schedule 13G                                                    PAGE 11 OF 14

          (j) (  )  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

         IF THIS STATEMENT IS FILED PURSUANT TO Rule 13d-1(c), CHECK THIS
BOX. [x]


ITEM 4.   OWNERSHIP.
     A.  CLSP
        (a)  Amount beneficially owned: 754,000
        (b)  Percent of class: 5.5%
              (All percentages  herein are based on 13,730,890  shares of Common
              Stock  reported to be  outstanding  as of November  10,  2000,  as
              reflected  in the  Company's  quarterly  report on Form 10-Q filed
              with the Securities and Exchange Commission by the Company for the
              quarter ended September 30, 2000.)
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         754,000
                  (iii)  sole power to dispose or to direct the  disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 754,000

B.  CLSP II
        (a)  Amount beneficially owned: 89,600
        (b)  Percent of class: 0.7%
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         89,600
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 89,600

     C.  CLSP/SBS I
        (a)  Amount beneficially owned: 214,400
        (b) Percent of class: 1.6%
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         214,400
                  (iii)  sole power to dispose or to direct the disposition
                         of 0





Schedule 13G                                                    PAGE 12 OF 14

                  (iv)   shared power to dispose or to direct the disposition
                         of 214,400

     D.  CLSP/SBS II
        (a)  Amount beneficially owned: 106,000
        (b)  Percent of class: 0.8%
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         106,000
                  (iv)   sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 106,000

     E.  Cooper Hill Partners, L.P.
        (a)  Amount beneficially owned: 196,300
        (b)  Percent of class: 1.4%
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         196,300
                  (iii)  sole power to dispose or to direct the disposition
                                     of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 196,300

     F.  Cooper LLC
        (a)  Amount beneficially owned: 1,164,000
        (b)  Percent of class: 8.5%
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         1,164,000
                  (iii)  sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                         of 1,164,000





Schedule 13G                                                    PAGE 13 OF 14

     G.  Jeffrey Casdin
        (a)  Amount beneficially owned: 1,360,300
        (b)  Percent of class: 9.9%
        (c)  Number of shares as to which such person has:
                  (i)    sole power to vote or to direct the vote
                         0
                  (ii)   shared power to vote or to direct the vote
                         1,360,300
                  (iv)   sole power to dispose or to direct the disposition
                         of 0
                  (iv)   shared power to dispose or to direct the disposition
                          of 1,360,300

ITEM 5.   OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.
          Not applicable.

ITEM 6.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

     CLSP,  CLSP II,  CLSP/SBS I, and  CLSP/SBS II are each  private  investment
partnerships,  the sole  general  partner of which is Cooper,  LLC.  As the sole
general partner of CLSP,  CLSP II, CLSP/SBS I, and CLSP/SBS II, Cooper,  LLC has
the power to vote and dispose of the Securities  owned by each of CLSP, CLSP II,
CLSP/SBS I, and  CLSP/SBS  II and,  accordingly,  may be deemed the  "beneficial
owner" of such Securities. The managing member of Cooper, LLC is Jeffrey Casdin.

     Pursuant to an investment  advisory  contract,  Cooper Hill Partners,  L.P.
currently  has the  power to vote and  dispose  of the  Securities  held for the
account of CLSP Overseas,  Ltd. and, accordingly,  may be deemed the "beneficial
owner" of such Securities.  Mr. Casdin is the managing member of Casdin Capital,
LLC, the general partner of Cooper Hill Partners, L.P.


ITEM 7.   IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
          THE SECURITY  BEING  REPORTED ON BY THE PARENT  HOLDING  COMPANY.  Not
          applicable.

ITEM 8.   IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.
          See Item 6.

ITEM 9.   NOTICE OF DISSOLUTION OF GROUP.
          Not applicable.





Schedule 13G                                                    PAGE 14 OF 14

ITEM 10.  CERTIFICATION.  (if filing pursuant to Rule 13d-1(c))

          Each of the Reporting Persons and CLSP Overseas,  Ltd. hereby make the
          following certification:

          By signing below each Reporting  Person certifies that, to the best of
its knowledge and belief, the securities referred to above were not acquired and
are not held for the purpose of or with the effect of  changing  or  influencing
the control of the issuer of the  Securities  and were not acquired and not held
in connection with or as a participant in any transaction having that purpose or
effect.


                                   SIGNATURES

      After reasonable  inquiry and to the best of our knowledge and belief, the
undersigned  certify that the  information  set forth in this statement is true,
complete and correct.

DATED:  March 9, 2001           /s/ Jeffrey Casdin,
                                    JEFFREY CASDIN, individually, and
                                    as managing member of Cooper Hill
                                    Partners, LLC, and on behalf of CLSP,
                                    L.P., CLSP II, L.P., CLSP/SBS I, L.P.,
                                    and CLSP/SBS II, L.P. and as managing
                                    member of Casdin Capital, L.L.C., the
                                    general partner of Cooper Hill Partners,
                                    L.P.