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                                                                 EXHIBIT 10.4.47


                           REVOLVING CREDIT LOAN NOTE

$1,500,000.00                                                   January 26, 2001
                                                                  Columbus, Ohio

         PROMISE TO PAY. Not later than January 25, 2002, for value received,
the undersigned, Neoprobe Corporation, a Delaware corporation (the "Borrower"),
hereby promises to pay to the order of Firstar Bank, N.A. (the "Bank") or its
assigns, as further provided herein, the principal amount of One Million Five
Hundred Thousand Dollars ($1,500,000) or, if such principal is less, the
aggregate unpaid principal amount of all Loans made by the Bank to the Borrower
pursuant to the Revolving Credit Loan Agreement referred to below, together with
interest on the unpaid principal balance from time to time outstanding hereunder
until paid in full at the rate(s) of interest determined in accordance with such
Revolving Credit Loan Agreement. Such interest and principal hereof shall be due
and payable on the dates set forth in such Revolving Credit Loan Agreement. Both
principal and interest are payable in federal funds or other immediately
available money of the United States of America at the main office of the Bank
located at 175 South Third Street, Columbus, Ohio 43215, or such other address
as the Bank may hereafter designate by notice to the Borrower.

         LOAN AGREEMENT. This Revolving Credit Loan Note is the Note referred to
in the Revolving Credit Loan Agreement between the Borrower and the Bank, dated
as of January 26, 2001, as the same may be amended, modified, supplemented,
extended, restated or replaced from time to time (the "Agreement"), which
Agreement is incorporated by reference herein. All capitalized terms used herein
shall have the same meanings as are assigned to such terms in the Agreement.
This Revolving Credit Loan Note is entitled to the benefits of and is subject to
the terms, conditions and provisions of the Agreement. The Agreement, among
other things, contains provisions for acceleration of the maturity hereof upon
the happening of certain stated events, and also for repayments and reborrowings
on account of the principal hereof prior to maturity upon the terms, conditions
and provisions specified therein. The Borrower and each endorser and any other
party liable on this Revolving Credit Loan Note severally waive demand,
presentment, notice of dishonor and protest, and consent to any extension or
postponement of time of its payment without limit as to the number or period, to
any substitution, exchange or release of all or part of any collateral securing
this Revolving Credit Loan Note, to the addition of any party, and to the
release or discharge of, or suspension of any rights and remedies against, any
Person who may be liable for the payment of this Revolving Credit Loan Note.

         The Bank is hereby authorized to record electronically or otherwise (i)
the date and amount of each Loan disbursement made by the Bank, (ii) the date
and amount of each payment or repayment of principal thereof, and (iii) such
other information as it deems necessary or appropriate, and may, if the Bank so
elects in connection with any transfer or enforcement of the Note, endorse on a
schedule forming a part thereof appropriate notation to evidence the foregoing
information with respect to each such Loans then outstanding. Such recordation
or endorsement shall constitute PRIMA FACIE evidence of the accuracy of the
information so recorded or endorsed; provided, however, the failure of the Bank
to make any such recordation(s) or endorsement(s) shall not affect the
obligation of the Borrower to repay outstanding principal, interest or any other
amount due hereunder or under the Note in accordance with the terms hereof and
the Agreement.


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WARRANT OF ATTORNEY. The Borrower hereby irrevocably authorizes any
attorney-at-law, including any attorney-at-law employed or retained by the Bank,
to appear for it in any action on this Revolving Credit Loan Note at any time
after the same becomes due as provided herein, in any court of record situated
in Franklin County, Ohio (which the Borrower acknowledges to be the place where
this Revolving Credit Loan Note was executed), in the county where the Borrower
then resides or can be found, to waive the issuing and service of process, and
confess a judgment in favor of the Bank or any other holder hereof against the
Borrower, for the amount that may then be due, with interest at the rate
provided for herein, together with the costs of suit, and to waive and release
all errors in said proceedings and the right to appeal from the judgment
rendered. The Borrower consents to the jurisdiction and venue of such court. The
Borrower waives any conflict of interest that any attorney-at-law employed or
retained by the Bank may have in confessing judgment hereunder and consents to
the payment of a legal fee to any attorney-at-law confessing judgment hereunder.


WARNING -- BY SIGNING THIS PAPER YOU GIVE UP YOUR RIGHT TO NOTICE AND COURT
TRIAL. IF YOU DO NOT PAY ON TIME A COURT JUDGMENT MAY BE TAKEN AGAINST YOU
WITHOUT YOUR PRIOR KNOWLEDGE AND THE POWERS OF A COURT CAN BE USED TO COLLECT
FROM YOU REGARDLESS OF ANY CLAIMS YOU MAY HAVE AGAINST THE CREDITOR WHETHER FOR
RETURNED GOODS, FAULTY GOODS, FAILURE ON HIS PART TO COMPLY WITH THE AGREEMENT,
OR ANY OTHER CAUSE.

                                       Neoprobe Corporation,
                                         a Delaware corporation


                                       By:    /s/ David Bupp
                                            ----------------------
                                       Name:    David Bupp
                                             ---------------------
                                       Title:    President, CEO
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