<PAGE>
                                                                   EXHIBIT 10.30

                              AMENDED AND RESTATED
                                 REVOLVING NOTE


$22,500,000                                                     Cincinnati, Ohio
                                                        Dated: September 20,2001
                                                         Restated: August 5,2004




         MERIDIAN BIOSCIENCE, INC., an Ohio corporation, MERIDIAN BIOSCIENCE
CORPORATION an Ohio corporation ("Corp."), OMEGA TECHNOLOGIES, INC., an Ohio
corporation ("Omega"), GULL LABORATORIES, INC. a Utah corporation ("Gull"),
BIODESIGN INCORPORATED, a Maine corporation and VIRAL ANTIGENS, INC., a
Tennessee corporation ("VAI") (collectively and jointly and severally the
"Borrowers" and individually a "Borrower"), for value received, hereby promises
to pay to the order of FIFTH THIRD BANK (the "Bank") at its offices, 38 Fountain
Square Plaza, Cincinnati, Ohio 45263, in lawful money of the United States
of America and in immediately available funds, the principal sum of $22,500,000
or such lesser unpaid principal amount as may be advanced by the Bank pursuant
to the terms of the Loan and Security Agreement dated September 20,2001 by and
among the Borrowers and the Bank, as same may be amended from time to time (the
"Agreement"). This Note shall mature and be payable in full on September
15, 2007, or such later date as may be determined and agreed upon between Bank
and Borrowers pursuant to the Agreement.

         The principal balance hereof outstanding from time to time shall bear
interest as set forth in the Agreement. Interest will be calculated based on a
360-day year and charged for the actual number of days elapsed, and will be
payable as set forth in the Agreement. After the occurrence of an Event of
Default, this Note shall bear interest (computed and adjusted in the same
manner, and with the same effect, as interest hereon prior to maturity), payable
on demand, at a rate per annum equal to six percent (6%) above the rate that
would otherwise be in effect, until paid, and whether before or after the entry
of judgment hereon.

         The principal amount of each loan made by the Bank and the amount of
each prepayment made by the Borrowers shall be recorded by the Bank on the
schedule attached hereto or in the regularly maintained data processing
records of the Bank. The aggregate unpaid principal amount of all loans set
forth in such schedule or in such records shall be presumptive evidence of the
principal amount owing and unpaid on this Note. However, failure by Bank to make
any such entry shall not limit or otherwise affect Borrowers' obligations under
this Note or the Agreement.

         This Note is the Revolving Note referred to in the Agreement, and is
entitled to the benefits, and is subject to the terms, of the Agreement. The
principal of this Note is prepayable in the amounts and under the circumstances,
and its maturity is subject to acceleration upon the terms, set forth in the
Agreement. Except as otherwise expressly provided in the Agreement, if any
payment on this Note becomes due and payable on a day other than one on which
Bank is open for business (a "Business Day"), the maturity there of shall be
extended to the next Business Day, and interest shall be payable at the rate
specified herein during such extension period.

         In no event shall the interest rate on this Note exceed the highest
rate permissible under any law which a court of competent jurisdiction shall, in
a final determination, deem applicable hereto. In the event that a court
determines that Bank has received interest and other charges under this Note in
excess of the highest permissible rate applicable hereto, such excess shall be
deemed received on account of, and shall automatically be applied to reduce the
amounts due to Bank from the Borrowers under this Note, other than interest, and
the provisions hereof shall be deemed amended to provide for the highest
permissible rate. If there are no such amounts outstanding, Bank shall refund to
Borrowers such excess.

         Borrowers and all endorsers, sureties, guarantors and other persons
liable on this Note hereby waive presentment for payment, demand, notice of
dishonor, protest, notice of protest and all other demands and notices in
connection with the delivery, performance and enforcement of this Note, and
consent to one or more renewals or extensions of this Note.


         This Note may not be changed orally, but only by an instrument in
writing.
<PAGE>

         This Note is being delivered in, is intended to be performed in, shall
be construed and enforceable in accordance with, and be governed by the internal
laws of, the State of Ohio without regard to principles of conflict of laws.
Borrowers agree that the State and federal courts in Hamilton County, Ohio or
any other court in which Bank initiates proceedings have exclusive jurisdiction
over all matters arising out of this Note, and that service of process in any
such proceeding shall be effective if mailed to Borrowers at their address
described in the Notices section of the Agreement. BORROWERS HEREBY WAIVE THE
RIGHT TO TRIAL BY JURY OF ANY MATTERS ARISING OUT OF THIS NOTE.



MERIDIAN BIOSCIENCE                           MERIDIAN BIOSCIENCE, INC.
CORPORATION

By: /s/ MELISSA LUEKE                         By:  /s/ MELISSA LUEKE
    ----------------------                         ---------------------------


Its: CFO                                      Its: CFO
    ----------------------                         ---------------------------


OMEGA TECHNOLOGIES, INC.                      GULL LABORATORIES, INC.

By: /s/ MELISSA LUEKE                         By:  /s/ MELISSA LUEKE
    ----------------------                         ---------------------------


Its: CFO                                      Its: CFO
    ----------------------                         ---------------------------

BIODESIGN INCORPORATED                        VIRAL ANTIGENS, INC.

By: /s/ MELISSA LUEKE                         By:  /s/ MELISSA LUEKE
    ----------------------                         ---------------------------


Its: CFO                                      Its: Treasurer-Secretary
    ----------------------                         ---------------------------




                                       2