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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                               (AMENDMENT NO. __)*



                               ON ASSIGNMENT, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)


                                  COMMON STOCK
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    682159108
--------------------------------------------------------------------------------
                                 (CUSIP Number)


                                 JANUARY 3, 2008
--------------------------------------------------------------------------------
             (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).



PERSONS WHO RESPOND TO THE COLLECTION OF INFORMATION CONTAINED IN THIS FORM ARE
NOT REQUIRED TO RESPOND UNLESS THE FORM DISPLAYS A CURRENTLY VALID OMB CONTROL
NUMBER.


                                       1


----------------------                                       -------------------
 CUSIP No.  682159108                 13G                     Page 2 of 9 Pages
----------------------                                       -------------------


    1.   NAMES OF REPORTING PERSONS

         Great Point Partners, LLC

         I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY):

         37-1475292

    2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
         (a)  |_|

         (b)  |_|

  ------------------------------------------------------------------------------
    3.      SEC USE ONLY

  ------------------------------------------------------------------------------

    4.   CITIZENSHIP OR PLACE OF ORGANIZATION

         USA

      NUMBER OF SHARES     5.  SOLE VOTING POWER

        BENEFICIALLY                                              0

       OWNED BY EACH       6.  SHARED VOTING POWER

      REPORTING PERSON                                       1,850,000

           WITH            7.  SOLE DISPOSITIVE POWER

                                                                  0

                           8.  SHARED DISPOSITIVE POWER

                                                             1,850,000


    9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  1,850,000

   10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
         (See Instructions)
                                                                             |_|

   11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  5.22%

   12.   TYPE OF REPORTING PERSON (See Instructions)

                  OO



----------------------                                       -------------------
 CUSIP No.  682159108                 13G                     Page 3 of 9 Pages
----------------------                                       -------------------


    1.   NAMES OF REPORTING PERSONS

         Dr. Jeffrey R. Jay, M.D.

         I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY):



    2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
         (a)  |_|

         (b)  |_|

  ------------------------------------------------------------------------------
    3.      SEC USE ONLY

  ------------------------------------------------------------------------------

    4.   CITIZENSHIP OR PLACE OF ORGANIZATION

         USA

      NUMBER OF SHARES     5.  SOLE VOTING POWER

        BENEFICIALLY                                              0

       OWNED BY EACH       6.  SHARED VOTING POWER

      REPORTING PERSON                                       1,850,000

           WITH            7.  SOLE DISPOSITIVE POWER

                                                                  0

                           8.  SHARED DISPOSITIVE POWER

                                                             1,850,000


    9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  1,850,000

   10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
         (See Instructions)
                                                                             |_|

   11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  5.22%

   12.   TYPE OF REPORTING PERSON (See Instructions)

                  IN




----------------------                                       -------------------
 CUSIP No.  682159108                 13G                     Page 4 of 9 Pages
----------------------                                       -------------------


    1.   NAMES OF REPORTING PERSONS

         Mr. David Kroin

         I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY):



    2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
         (a)  |_|

         (b)  |_|

  ------------------------------------------------------------------------------
    3.      SEC USE ONLY

  ------------------------------------------------------------------------------

    4.   CITIZENSHIP OR PLACE OF ORGANIZATION

         USA

      NUMBER OF SHARES     5.  SOLE VOTING POWER

        BENEFICIALLY                                              0

       OWNED BY EACH       6.  SHARED VOTING POWER

      REPORTING PERSON                                       1,850,000

           WITH            7.  SOLE DISPOSITIVE POWER

                                                                  0

                           8.  SHARED DISPOSITIVE POWER

                                                             1,850,000


    9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  1,850,000

   10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
         (See Instructions)
                                                                             |_|

   11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  5.22%

   12.   TYPE OF REPORTING PERSON (See Instructions)

                  IN




----------------------                                       -------------------
 CUSIP No.  682159108                 13G                     Page 5 of 9 Pages
----------------------                                       -------------------


    ITEM 1.

                    (a)  Name of Issuer

                         On Assignment, Inc.

                    (b)  Address of Issuer's Principal Executive Offices

                         26651 West Agoura Road, Calabasas Ca 91302

    ITEM 2.

                    (a)  Name of Person Filing

                              Great Point Partners, LLC
                              Dr. Jeffrey R. Jay, M.D.
                              Mr. David Kroin

                    The Reporting Persons have entered into a Joint Filing
                    Agreement, dated January 14, 2008, a copy of which is filed
                    with this Schedule 13G as Exhibit A, pursuant to which the
                    Reporting Persons have agreed to file this statement jointly
                    in accordance with the provisions of Rule 13d-1(k)(1) under
                    the Act.

                    (b)  Address of Principal Business Office, or if none,
                         Residence

                         The address of the principal business office of each of
                         the Reporting Persons is

                             165 Mason Street, 3rd Floor
                             Greenwich, CT 06830

                    (c)  Citizenship

                    Great Point Partners, LLC is a limited liability company
                    organized under the laws of the State of Delaware. Dr.
                    Jeffrey R. Jay, M.D. is a citizen of the United States. Mr.
                    David Kroin is a citizen of the United States.

                    (d)  Title of Class of Securities

                         Common Stock

                    (e)  CUSIP Number

                         682159108

    ITEM 3.         IF THIS STATEMENT IS FILED PURSUANT TO SS.240.13D-1(B) OR
                    240.13D.2(B) OR (C), CHECK WHETHER THE PERSON FILING IS A:

                             Not Applicable.

                    (a)  |_|  Broker or dealer registered under Section 15 of
                              the Act (15 U.S.C. 78o)

                    (b)  |_|  Bank as defined in Section 3(a)(6) of the Act
                              (15 U.S.C. 78c).

                    (c)  |_|  Insurance company as defined in Section 3(a)(19)
                              of the Act (15. U.S.C. 78c).

                    (d)  |_|  Investment Company registered under Section 8 of
                              the Investment Company Act of 1940
                              (15 U.S.C. 80a-8).

                    (e)  |_|  An investment adviser in accordance with
                              ss.240.13d-1(b)(1)(ii)(E).



----------------------                                       -------------------
 CUSIP No.  682159108                 13G                     Page 6 of 9 Pages
----------------------                                       -------------------


                    (f)  |_|  An employee benefit plan or endowment fund in
                              accordance with ss.240.13d-1(b)(1)(ii)(F).

                    (g)  |_|  A parent holding company or control person in
                              accordance with ss.240.13d-1(b)(1)(ii)(G).

                    (h)  |_|  A savings associations as defined in Section
                              3(b) of the Federal Deposit Insurance Act (12
                              U.S.C. 1813).

                    (i)  |_|  A church plan that is excluded from the
                              definition of an investment company under
                              Section 3(c)(14) of the Investment Company Act
                              of 1940 (15 U.S.C. 80a-3).

                    (j)  |_|  Group, in accordance with
                              ss.240.13d-1(b)(1)(ii)(J).

    ITEM 4.         OWNERSHIP

                    Great Point Partners, LLC ("Great Point") is the investment
                    manager of Biomedical Value Fund, L.P. ("BVF"), and by
                    virtue of such status may be deemed to be the beneficial
                    owner of the 999,003 shares of Common Stock of the Issuer
                    owned by BVF (the "BVF Shares"). Each of Dr. Jeffrey R. Jay,
                    M.D. ("Dr. Jay"), as senior managing member of Great Point,
                    and Mr. David Kroin ("Mr. Kroin"), as special managing
                    member of Great Point, has voting and investment power with
                    respect to the BVF Shares, and therefore may be deemed to be
                    the beneficial owner of the BVF Shares.

                    Great Point is the investment manager of Biomedical Offshore
                    Value Fund, Ltd. ("BOVF"), and by virtue of such status may
                    be deemed to be the beneficial owner of the 850,997 shares
                    of Common Stock of the Issuer owned by BOVF (the "BOVF
                    Shares"). Dr. Jay, as senior managing member of Great Point,
                    and Mr. Kroin, as special managing member of Great Point,
                    has voting and investment power with respect to the BOVF
                    Shares, and therefore may be deemed to be the beneficial
                    owner of the BOVF Shares.

                    Each of Great Point, Dr. Jay and Mr. Kroin disclaim
                    beneficial ownership of the BVF Shares and the BOVF Shares,
                    except to the extent of their respective pecuniary interest.


                    Provide the following information regarding the aggregate
                    number and percentage of the class of securities of the
                    issuer identified in Item 1.

                    1. GREAT POINT PARTNERS, LLC

                    (a)  Amount beneficially owned: 1,850,000

                    (b)  Percent of class: 5.22%

                    (c)  Number of shares as to which the person has:

                         (i)    Sole power to vote or to direct the vote:  - 0 -

                         (ii)   Shared power to vote or to direct the vote:
                                1,850,000

                         (iii)  Sole power to dispose or to direct the
                                disposition of:   - 0 -.

                         (iv)   Shared power to dispose or to direct the
                                disposition of: 1,850,000

                    2.   DR. JEFFREY R. JAY, M.D.

                    (a)  Amount beneficially owned: 1,850,000

                    (b)  Percent of class: 5.22%



----------------------                                       -------------------
 CUSIP No.  682159108                 13G                     Page 7 of 9 Pages
----------------------                                       -------------------


                    (c)  Number of shares as to which the person has:

                         (i)   Sole power to vote or to direct the vote: 0.

                         (ii)  Shared power to vote or to direct the vote:
                               1,850,000

                         (iii) Sole power to dispose or to direct the
                               disposition of: 0.

                         (iv)  Shared power to dispose or to direct the
                               disposition of: 1,850,000

                    3.   MR. DAVID KROIN

                    (a)  Amount beneficially owned: 1,850,000

                    (b)  Percent of class: 5.22%

                    (c)  Number of shares as to which the person has:

                         (i)   Sole power to vote or to direct the vote: 0.

                         (ii)  Shared power to vote or to direct the vote:
                               1,850,000

                         (iii) Sole power to dispose or to direct the
                               disposition of: 0.

                         (iv)  Shared power to dispose or to direct the
                               disposition of: 1,850,000


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:

                    See Item 4.

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

                    Not Applicable.

ITEM 9.             NOTICE OF DISSOLUTION OF GROUP

                    Not Applicable.

ITEM 10.            CERTIFICATION

By signing below I certify that, to the best of my 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 are not held in connection with or as
participant in any transaction having that purpose or effect.




----------------------                                       -------------------
 CUSIP No.  682159108                 13G                     Page 8 of 9 Pages
----------------------                                       -------------------


                                    SIGNATURE

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

Date:  January 14, 2008

                                         GREAT POINT PARTNERS, LLC

                                         By: /s/ DR. JEFFREY R. JAY, M.D.
                                             ----------------------------------
                                             Dr. Jeffrey R. Jay, M.D.,
                                              as senior managing member

                                         /s/ DR. JEFFREY R. JAY, M.D.
                                         --------------------------------------
                                         DR. JEFFREY R. JAY, M.D.

                                         /s/ MR. DAVID KROIN
                                         --------------------------------------
                                         MR. DAVID KROIN








                                                                       EXHIBIT A


              AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13G


The undersigned hereby agree as follows:

         (i) Each of them is individually eligible to use the Schedule 13G to
which this Exhibit is attached, and such Schedule 13G is filed on behalf of each
of them; and

         (ii) Each of them is responsible for the timely filing of such Schedule
13G and any amendments thereto, and for the completeness and accuracy of the
information concerning such person contained therein; but none of them is
responsible for the completeness or accuracy of the information concerning the
other persons making the filing, unless such person knows or has reason to
believe that such information is inaccurate.

Date:  January 14, 2008

                                            GREAT POINT PARTNERS, LLC

                                            By: /s/ DR. JEFFREY R. JAY, M.D.
                                                --------------------------------
                                                Dr. Jeffrey R. Jay, M.D.,
                                                 as senior managing member


                                            /s/ DR. JEFFREY R. JAY, M.D.
                                            ------------------------------------
                                            DR. JEFFREY R. JAY, M.D.

                                            /s/ MR. DAVID KROIN
                                            ------------------------------------
                                            MR. DAVID KROIN