<PAGE>

                                                                   Exhibit 10.7

          The securities represented hereby have not been registered
     under the Securities Act of 1933, as amended, or any state
     securities laws and neither the securities nor any interest
     therein may be offered, sold, transferred, pledged or otherwise
     disposed of except pursuant to an effective registration
     statement under such Act and such laws or an exemption from
     registration under such Act and such laws which, in the opinion of
     counsel for the holder, which counsel and opinion are reasonably
     satisfactory to counsel for this corporation, is available.

                                     NOTE

$200,000.00                                            February 16, 2001

     For value received, the undersigned, SERACARE, INC., a Delaware
corporation having an address at 1925 Century Park East, Suite 1970, Los
Angeles, Ca 90067 (the "BORROWER"), hereby promises to pay to the order of
Samuel A. and Mary Ann Anderson Trust, 63 Beacon Bay, Newport Beach, CA 92660
(the "PAYEE"), the principal sum of Two Hundred Thousand Dollars
($200,000.00), on March 30, 2001, together with all accrued interest through
and including the date of payment (the "INITIAL MATURITY DATE"). At the
option of the borrower, the Maturity Date may be extended through and until
June 14, 2001 (the "FINAL MATURITY DATE"), Interest shall be payable at a
rate per annum (computed for actual days elapsed on the basis of a 365-day
year) of twelve percent (12.0%). The Borrower may prepay this Note at any
time prior to the due date hereof, in full, without premium or penalty.

     Payments of both principal and interest on this Note are to be made at
63 Beacon Bay, Newport Beach, CA 92660, or such other place as the holder
hereof shall designate to the Borrower in writing, in lawful money of the
United States of America in immediately available funds.

     The Borrower shall pay reasonable costs and expenses of collection,
including, without limitation, reasonable attorney's fees and disbursements
in the event that any action, suit or proceeding is brought by the holder
hereof to collect this Note and either the holder obtains a judgment in its
favor that is not appealed from or is upheld on appeal, or such action, suite
or proceeding is settled with any sum due and owing to the holder as a result
of such settlement.

     THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED AND ENFORCED IN ACCORDANCE
WITH, THE LAWS OF THE STATE OF CALIFORNIA WITHOUT REGARD TO ITS RULES
PERTAINING TO CONFLICT OF LAWS.


<PAGE>


     THE BORROWER IRREVOCABLY CONSENTS THAT ANY LEGAL ACTION OR PROCEEDING
AGAINST IT UNDER, ARISING OUT OF OR IN ANY MANNER RELATING TO THIS NOTE MAY
BE BROUGHT IN ANY COURT OF THE STATE OF NEW YORK, COUNTY OF NEW YORK, OR IN
THE UNITED STATES DISTRICT COURT FOR THE STATE OF NEW YORK OR IN THE STATE OF
CALIFORNIA, OR IN THE UNITED STATES DISTRICT COURT FOR THE STATE OF
CALIFORNIA. THE BORROWER, BY THE EXECUTION AND DELIVERY OF THIS NOTE,
EXPRESSLY AND IRREVOCABLY ASSENTS AND SUBMITS TO THE PERSONAL JURISDICTION
OF ANY OF SUCH COURT IN ANY SUCH ACTION OR PROCEEDING. BY ITS ACCEPTANCE OF
THIS NOTE BY THE HOLDER AND BY THE EXECUTION HEREOF BY THE BORROWER, EACH
AGREES THAT ANY AND ALL LEGAL ACTION RELATING TO THIS NOTE SHALL BE BROUGHT,
AND MAINTAINED, ONLY IN SUCH COURTS. THE BORROWER FURTHER IRREVOCABLY
CONSENTS TO THE SERVICE OF ANY COMPLAINT, SUMMONS, NOTICE OR OTHER PROCESS
RELATING TO ANY SUCH ACTION OR PROCEEDING BY DELIVERY THEREOF TO IT AT THE
ADDRESS SET FORTH ABOVE OR SUCH OTHER ADDRESS AS THE BORROWER SHALL HAVE
THERETOFORE NOTIFIED THE HOLDER HEREOF IN WRITING OR IN ANY OTHER MANNER
PERMITTED BY LAW. IN THE EVENT SERVICE ON THE BORROWER IS EFFECTED AS SET
FORTH IN THE PRECEDING SENTENCE, THE BORROWER HEREBY EXPRESSLY AND
IRREVOCABLY WAIVES ANY CLAIM OR DEFENSE IN ANY SUCH ACTION OR PROCEEDING
BASED ON ANY ALLEGED LACK OF PERSONAL JURISDICTION, IMPROPER VENUE, FORUM NON
CONVENIENS, OR ANY SIMILAR BASIS.


                                       SERACARE, INC.



                                        By: /s/ JERRY L. BURDICK
                                           --------------------------