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EXHIBIT *(10.22)

                              REVOLVING CREDIT NOTE


$12,000,000.00                                                October 29, 1999



      FOR VALUE RECEIVED, and intending to be legally bound, the undersigned,
IGI, INC., IGEN, INC., IMMUNOGENETICS, INC., and BLOOD CELLS, INC., each a
Delaware corporation (collectively, "Borrowers," and severally, each a
"Borrower") promises to pay to the order of Fleet Capital Corporation
("Lender"), in such coin or currency of the United States which shall be legal
tender in payment of all debts and dues, public and private, at the time of
payment, the principal sum of Twelve Million Dollars($12,000,000.00) or such
lesser sum which then represents the aggregate unpaid principal balance of
Revolving Credit Loans, together with interest from and after the date hereof on
the unpaid principal balance outstanding at the rates per annum set forth in the
Loan Agreement (as defined below). Interest shall be computed in the manner
provided in Section 2 of the Loan Agreement.

      This Revolving Credit Note (the "Note") is the Revolving Credit Note
referred to in, and is issued pursuant to, that certain Loan and Security
Agreement among Borrowers and Lender, dated the date hereof (as amended from
time to time, the "Loan Agreement"), and is entitled to all of the benefits and
security of the Loan Agreement. All of the terms, covenants and conditions of
the Loan Agreement and the Security Documents are hereby made a part of this
Note and are deemed incorporated herein in full. All capitalized terms used
herein, unless otherwise specifically defined in this Note, shall have the
meanings ascribed to them in the Loan Agreement.

      The principal amount and accrued interest on this Note shall be due and
payable on the dates and in the manner hereinafter set forth:

            (a) Interest shall be due and payable monthly, in arrears, on the
      first day of each month, commencing on the first day of the first month
      following the date hereof, and continuing until such time as the full
      principal balance, together with all other amounts owing hereunder, shall
      have been paid in full.

            (b) Principal shall be due and payable in accordance with the Loan
      Agreement and all outstanding principal, together with any and all other
      unpaid amounts hereunder, shall in any event be due and payable on the
      Revolving Credit Maturity Date.

      Notwithstanding the foregoing, the entire unpaid principal balance and
accrued interest on this Note shall be due and payable immediately upon the
earlier of acceleration of the Obligations following an Event of Default under
the Loan Agreement or termination of the Loan Agreement pursuant to Section 4
thereof.

      This Note shall be subject to prepayment (and prepayment premium, if
applicable) in accordance with the provisions of Section 3.3 of the Loan
Agreement. Borrower may also terminate the Loan Agreement and, in connection
with such termination, prepay this Note in the manner and subject to the
conditions provided in Section 4 of the Loan Agreement.


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      Upon the occurrence of an Event of Default, Lender shall have all of the
rights and remedies set forth in Section 10 of the Loan Agreement or as
available at law or in equity to protect and enforce Lender's rights hereunder.

      Time is of the essence under this Note. To the fullest extent permitted by
applicable law, each Borrower, for itself and its legal representatives,
successors and assigns, expressly waives presentment, demand, protest, notice of
dishonor, notice of non-payment, notice of maturity, notice of protest,
presentment for the purpose of accelerating maturity, and diligence in
collection.

      Wherever possible, each provision of this Note shall be interpreted in
such manner as to be effective and valid under applicable law, but if any
provision of this Note shall be prohibited or invalid under applicable law, such
provision shall be ineffective to the extent of such prohibition or invalidity
without invalidating the remainder of such provision or remaining provisions of
this Note. No delay or failure on the part of Lender in the exercise of any
right or remedy hereunder shall operate as a waiver thereof, nor as an
acquiescence in any default, nor shall any single or partial exercise by Lender
of any right or remedy preclude any other right or remedy. Lender, at its
option, may enforce its rights against any Collateral securing this Note without
enforcing its rights against Borrowers (or any one or more of them) or any other
property to Borrower. Each Borrower agrees that, without releasing or impairing
Borrowers' liability hereunder, Lender may at any time release, surrender,
substitute or exchange any Collateral securing this Note and may at any time
release any party primarily or secondarily liable for the indebtedness evidenced
by this Note.

     IN ANY LITIGATION ARISING OUT OF OR RELATING TO ANY OF THE MATTERS
CONTAINED IN THIS NOTE OR ANY OF THE DOCUMENTS DELIVERED IN CONNECTION HEREWITH
IN WHICH LENDER AND BORROWER ARE ADVERSE PARTIES, THE LENDER AND EACH BORROWER
WAIVE TRIAL BY JURY.

      This Note shall be governed by, and construed and enforced in accordance
with, the laws of the State of Pennsylvania. All obligations of Borrower
hereunder shall be joint and several.

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      IN WITNESS WHEREOF, Borrowers have caused this Note to be duly executed
and delivered on the date first above written.

                                    IGI, INC.
Attest:

/s/ Robert E. McDaniel              By:   /s/ Manfred Hanuschek
---------------------------               ------------------------------------

                                    Name: Manfred Hanuschek
                                          ------------------------------------
                                    Title: CFO
                                          ------------------------------------


                                    IGEN, INC.
Attest:

/s/ Robert E. McDaniel              By:   /s/ Manfred Hanuschek
---------------------------               ------------------------------------

                                    Name: Manfred Hanuschek
                                          ------------------------------------
                                    Title: CFO
                                          ------------------------------------


                                    IMMUNOGENETICS, INC.
Attest:

/s/ Robert E. McDaniel              By:   /s/ Manfred Hanuschek
---------------------------               ------------------------------------

                                    Name: Manfred Hanuschek
                                          ------------------------------------
                                    Title: CFO
                                          ------------------------------------


                                    BLOOD CELLS, INC.
Attest:

/s/ Robert E. McDaniel              By:   /s/ Manfred Hanuschek
---------------------------               ------------------------------------

                                    Name: Manfred Hanuschek
                                          ------------------------------------
                                    Title: CFO
                                          ------------------------------------


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