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                                                                     EXHIBIT 4.9

                                     WARRANT
                                       TO
                              PURCHASE COMMON STOCK
                                       OF
                              NEOPROBE CORPORATION

         THIS WARRANT MAY NOT BE OFFERED FOR SALE, SOLD OR OTHERWISE TRANSFERRED
UNLESS IT IS REGISTERED UNDER THE SECURITIES ACT OF 1933 OR IT OR SUCH OFFER,
SALE OR TRANSFER IS EXEMPT FROM SUCH REGISTRATION AND THE COMPANY HAS RECEIVED
AN OPINION OF COUNSEL, REASONABLY SATISFACTORY TO THE COMPANY IN FORM AND
SUBSTANCE, TO THAT EFFECT.


NO. WK001                                WARRANT TO PURCHASE 50,000 SHARES OF
                                         COMMON STOCK, PAR VALUE $.001 PER SHARE
                                         (SUBJECT TO ADJUSTMENT)



         For value received, NEOPROBE CORPORATION, a Delaware corporation (the
"Company"), hereby certifies that ENZON, INC., a Delaware corporation, or its
registered assigns (the "Holder"), is entitled, subject to the terms set forth
below, to purchase from the Company Fifty Thousand (50,000) shares of the Common
Stock, par value $.001 per share, of the Company ("Common Stock"), as
constituted on March 28, 1996 (the "Warrant Issue Date"), upon surrender hereof
at the principal office of the Company referred to below, with the Notice of
Exercise attached hereto duly executed, and simultaneous payment therefor in
lawful money of the United States as hereinafter provided at the per share
exercise price of $6.30 (the "Exercise Price"). The number, character and
Exercise Price of such shares of Common Stock are subject to adjustment as
provided below. The term "Warrant" as used herein shall include this Warrant and
any warrants delivered in substitution or exchange therefor as provided herein.
This Warrant is registered and its transfer may be registered upon the books
maintained for that purpose by the Company by delivery of this Warrant duly
endorsed.

ARTICLE 1. Term of Warrant. Subject to the terms and conditions set forth
herein, this Warrant shall be exercisable during the term commencing on the
Warrant Issue Date and ending at 5:00 p.m., Eastern time, on the later of
November 11, 1996 or 90 days after the effective date of a registration
statement under the Securities Act of 1933 (the "Act") for this Warrant and the
shares of Common Stock issued hereunder, and shall be void thereafter.

ARTICLE 2.  Exercise of Warrant.

         SECTION 2.1. Method. The purchase rights represented by this Warrant
are exercisable by the Holder, in whole or in part, at any time or from time to
time, during the term hereof by the surrender of this Warrant and the Notice of
Exercise annexed hereto duly completed and executed by the Holder at the
principal executive office of the Company at 425 Metro Place North, Dublin, Ohio
43017-1367 (or such other office or agency of the Company as it may designate by
notice in writing to the Holder), together with the consideration constituting
the Exercise Price of the shares to be purchased in cash or by wire transfer to
a bank account designated by the Company or by a certified check; provided,
however, that if less than all of the purchase rights represented by this
Warrant are exercised, such exercise shall involve the purchase of at least One
Hundred (100) shares of Common Stock.

         SECTION 2.2. Effect. This Warrant shall be deemed to have been
exercised at the time of its surrender for exercise together with full payment
as provided above, and the person entitled to receive the shares of Common Stock
issuable upon such exercise shall be treated for all purposes as the holder of
record of such shares at and after 
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such time. As promptly as practicable on or after such date the Company at its
expense shall issue to the person entitled to receive the same a certificate for
the number of shares of Common Stock issuable upon such exercise. If this
Warrant is exercised in part, the Company at its expense will execute and
deliver a new Warrant exercisable for the number of shares for which this
Warrant may then be exercised.

         SECTION 2.3. Holder Not a Shareholder. The Holder shall neither be
entitled to vote nor receive dividends nor be deemed the holder of Common Stock
or any other securities of the Company that may at any time be issuable on the
exercise hereof for any purpose until the Warrant has been exercised as provided
in this Article 2.

         SECTION 2.4. No Fractional Shares. No fractional shares of Common Stock
shall be issued upon the exercise of this Warrant. In lieu of any fractional
share to which the Holder would otherwise be entitled, the Company shall make a
cash payment equal to the closing market price of a share of Common Stock on the
date of exercise multiplied by such fraction.

ARTICLE 3.  Registered Warrants.

         SECTION 3.1. Series. This Warrant is one of a numbered series of
Warrants which are identical except as to the number of shares of Common Stock
purchasable and as to any restriction on the transfer thereof in order to comply
with the Act and the regulations of the Securities and Exchange Commission
promulgated thereunder or state securities or blue sky laws. Such Warrants are
referred to herein collectively as the "Warrants."

         SECTION 3.2. Record Ownership. The Company shall maintain a register of
the Holders of the Warrants (the "Register") showing their names and addresses
and the serial numbers and number of shares of Common Stock purchasable issued
to or transferred of record by them from time to time. The Register may be
maintained in electronic, magnetic or other computerized form. The Company may
treat the person named as the Holder of this Warrant in the Register as the sole
owner of this Warrant. The Holder of this Warrant is the person exclusively
entitled to receive notifications with respect to this Warrant, exercise it to
purchase shares of Common Stock and otherwise exercise all of the rights and
powers as the absolute owner hereof.

         SECTION 3.3. Registration of Transfer. Transfers of this Warrant may be
registered on the Register. Transfers shall be registered when this Warrant is
presented to the Company duly endorsed with a request to register the transfer
hereof. When this Warrant is presented for transfer and duly transferred
hereunder, it shall be canceled and a new Warrant showing the name of the
transferee as the Holder thereof shall be issued in lieu hereof, provided,
however, that no transfer of less than all of this Warrant shall be made if the
portion to be transferred is less than One Hundred (100) shares of Common Stock.
When this Warrant is presented to the Company with a reasonable request to
exchange it for Warrants of other denominations of at least One Hundred (100)
shares of Common Stock, the Company shall make such exchange and shall cancel
this Warrant and issue in lieu thereof Warrants exercisable for an equal number
of shares of Common Stock in the denominations requested by the Holder. Such
Warrants shall bear the legend set forth in the face hereof, unless the Company
receives an opinion of counsel, reasonably satisfactory to the Company in form
and substance, stating that any Warrants to be issued upon any transfer or
exchange pursuant to this Section 3.3 are no longer required to bear such
legend.

         SECTION 3.4. Worn and Lost Warrants. If this Warrant becomes worn,
defaced or mutilated but is still substantially intact and recognizable, the
Company or its agent may issue a new Warrant in lieu hereof upon its surrender.
If this Warrant is lost, destroyed or wrongfully taken, the Company shall issue
a new Warrant in place of the original Warrant if the Holder so requests by
written notice to the Company and the Holder has delivered to the Company an
indemnity agreement reasonably satisfactory to the Company with an affidavit of
the Holder that this Warrant has been lost, destroyed or wrongfully taken. Such
Warrants shall bear the legend set forth on the face hereof, unless the Company
receives an opinion of counsel, reasonably satisfactory to the Company in form
and substance, stating that any Warrants to be issued in place of any Warrants
pursuant to this Section 3.4 are not required to bear such legend under the Act.


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         SECTION 3.5. Restrictions on Transfer and Exercise. This Warrant and
the Common Stock issuable upon the exercise of this Warrant may not be offered
for sale, sold or otherwise transferred unless such offer, sale or other
transfer is registered under the Act or such securities or such transfer is
exempt from such registration and the Company has received an opinion of
counsel, reasonably satisfactory to the Company in form and substance, stating
that such securities or such offer, sale or transfer is exempt from registration
under the Act. This Warrant may not be exercised unless the exercise hereof is
registered under the Act or the securities issuable hereunder are exempt from
registration or such exercise is exempt from registration under the Act and the
Company has received an opinion of counsel or other evidence of such exemption,
reasonably satisfactory to the Company in form and substance, stating that such
securities or such exercise is exempt from registration under the Act.

         SECTION 3.6. Legend. Upon any exercise of this Warrant, the
certificates representing the securities purchased thereby shall bear the
following legend, unless (a) such securities shall have been registered under
the Act or (b) the purchaser shall have provided to the Company an opinion of
counsel, reasonably satisfactory to the Company in form and substance, stating
that such is not required by the Act:

               THESE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD OR
               OTHERWISE TRANSFERRED UNLESS THEY ARE REGISTERED UNDER THE
               APPROPRIATE SECURITIES LAWS OR THEY OR SUCH OFFER, SALE OR
               OTHER TRANSFER IS EXEMPT FROM SUCH REGISTRATION AND THE
               COMPANY HAS RECEIVED AN OPINION OF COUNSEL TO THAT EFFECT,
               REASONABLY SATISFACTORY TO THE COMPANY IN FORM AND SUBSTANCE.

         SECTION 3.7. Warrant Agent. The Company may, by written notice to the
Holder, appoint an agent for the purpose of maintaining the Register, issuing
Common Stock or other securities then issuable upon the exercise of this
Warrant, exchanging or transferring this Warrant, or any or all of the
foregoing. Thereafter, any such registration, issuance, exchange, or transfer,
as the case may be, shall be made at the office of such agent.

ARTICLE 4. Amendment to License and Development Agreement. Sections 3, 4, 5, 6,
7, 8, 9, 10, and 11 of an Amendment To License and Development Agreement dated
March 28, 1996 between the Holder and the Company (the "Agreement") are
incorporated into this Warrant and made a part of this Warrant and the terms of
such sections of the Agreement shall govern in the event there is any
inconsistency between this Warrant and such sections of the Agreement.

ARTICLE 5. Reservation of Stock. The Company covenants that, during the term
this Warrant is exercisable, the Company will reserve from its authorized and
unissued Common Stock or Common Stock held in treasury a sufficient number of
shares to provide for the issuance of Common Stock upon the exercise of this
Warrant. The Company further covenants that all shares that may be issued upon
the exercise of rights represented by this Warrant, upon exercise of the rights
represented by this Warrant and payment of the Exercise Price, all as set forth
herein, will be duly authorized, validly issued, fully paid, non-assessable and
free from all taxes, liens and charges in respect of the issue thereof (other
than taxes in respect of any transfer occurring contemporaneously or otherwise
specified herein). The Company agrees that its issuance of this Warrant shall
constitute full authority to its officers who are charged with the duty of
executing stock certificates to execute and issue the necessary certificates for
shares of Common Stock upon the exercise of this Warrant.

ARTICLE 6. Adjustments. The Exercise Price and the number of shares purchasable
hereunder are subject to adjustment from time to time as follows:

         SECTION 6.1. Merger, Sale of Assets, etc. If, at any time while this
Warrant or any portion thereof is outstanding and unexpired, there shall be (a)
a reorganization (other than a combination, reclassification, exchange or
subdivision of shares otherwise provided for herein), (b) a merger or
consolidation of the Company with or into another corporation in which the
Company is not the surviving entity, or a reverse triangular merger in which the
Company is the surviving entity but the shares of the Company's capital stock
outstanding immediately prior to the 


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merger are converted by virtue of the merger into other property, whether in the
form of securities, cash, or otherwise, or (c) a sale or transfer of the
Company's properties and assets as, or substantially as, an entirety to any
other person, then, as a part of such reorganization, merger, consolidation,
sale or transfer, lawful provision shall be made so that the holder of this
Warrant shall thereafter be entitled to receive upon exercise of this Warrant,
during the period specified herein and upon payment of the Exercise Price then
in effect, the number of shares of stock or other securities or property of the
successor corporation resulting from such reorganization, merger, consolidation,
sale or transfer that a holder of the shares deliverable upon exercise of this
Warrant would have been entitled to receive in such reorganization,
consolidation, merger, sale or transfer if this Warrant had been exercised
immediately before such reorganization, merger, consolidation, sale or transfer,
all subject to further adjustment as provided in this Article 6. The foregoing
provisions of this Section 6.1 shall similarly apply to successive
reorganizations, consolidations, mergers, sales and transfers and to the stock
or securities of any other corporation that are at the time receivable upon the
exercise of this Warrant. If the per share consideration payable to the Holder
hereof for shares in connection with any such transaction is in a form other
than cash or marketable securities, then the value of such consideration shall
be determined in good faith by the Company's Board of Directors, which
determination shall be conclusive in the absence of manifest error. In all
events, appropriate adjustment (as determined in good faith by the Company's
Board of Directors, which determination shall be conclusive in the absence of
manifest error) shall be made in the application of the provisions of this
Warrant with respect to the rights and interests of the Holder after the
transaction, to the end that the provisions of this Warrant shall be applicable
after that event, as near as reasonably may be, in relation to any shares or
other property deliverable after that event upon exercise of this Warrant.

         SECTION 6.2. Reclassification, etc. If the Company, at any time while
this Warrant or any portion thereof remains outstanding and unexpired, by
reclassification of securities or otherwise, shall change any of the securities
as to which purchase rights under this Warrant exist into the same or a
different number of securities of any other class or classes, this Warrant shall
thereafter represent the right to acquire such number and kind of securities as
would have been issuable as the result of such change with respect to the
Warrant immediately prior to such reclassification or other change and the
Exercise Price therefor shall be appropriately adjusted, all subject to further
adjustment as provided in this Article 6.

         SECTION 6.3. Split, Subdivision or Combination of Shares. If the
Company, at any time while this Warrant or any portion thereof remains
outstanding and unexpired, shall split, subdivide or combine the securities as
to which purchase rights under this Warrant exist, into a different number of
securities of the same class, the Exercise Price of such securities shall be
proportionately decreased in the case of a split or subdivision or
proportionately increased in the case of a combination, and the number of shares
of Common Stock for which this Warrant is exercisable shall be proportionately
increased in the case of a split or subdivision or proportionately decreased in
the case of a combination.

         SECTION 6.4. Adjustments for Dividends in Stock or Other Securities or
Property. If, while this Warrant or any portion hereof remains outstanding and
unexpired, the holders of the securities as to which purchase rights under this
Warrant exist at the time shall have received, or, on or after the record date
fixed for the determination of eligible shareholders, shall have become entitled
to receive, without payment therefor, other or additional stock or other
securities or property (other than cash) of the Company by way of dividend,
then, and in each case, this Warrant shall represent the right to acquire, in
addition to the number of shares of the security receivable upon exercise of
this Warrant, and without payment of any additional consideration therefor, the
amount of such other or additional stock or other security or property (other
than cash) of the Company that such holder would hold on the date of such
exercise had it been the holder of record of the security receivable upon
exercise of this Warrant on the date hereof and had thereafter, during the
period from the date hereof to and including the date of such exercise, retained
such shares and/or all other additional stock available by it as aforesaid
during such period, giving effect to all adjustments called for during such
period by the provisions of this Article 6.

         SECTION 6.5. Certificate as to Adjustments. Upon the occurrence of each
adjustment pursuant to this Article 6, the Company at its expense shall promptly
compute such adjustment in accordance with the terms hereof and furnish to the
Holder a certificate setting forth such adjustment and showing in detail the
facts upon which 


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such adjustment is based, and the Exercise Price before and after the
adjustment. The Company shall, at any time upon the written request of any
Holder, furnish to such Holder a certificate setting forth: (a) such
adjustments; (b) the Exercise Price then in effect; and (c) the number of shares
and the amount, if any, of other property that at the time would be received
upon the exercise of the Warrant.

         SECTION 6.6. No Impairment. The Company will not, by any voluntary
action, avoid or seek to avoid the observance or performance of any of the terms
to be observed or performed hereunder by the Company, but will at all times in
good faith assist in the carrying out of all the provisions of this Article 6
and in the taking of all such actions as may be necessary or appropriate in
order to protect the rights of the Holder of this Warrant against impairment.

ARTICLE 7. Distributions. If: (a) the Company sets a record date for the holders
of its Common Stock (or other stock or securities at the time receivable upon
the exercise of this Warrant) for the purpose of entitling them to receive any
dividend or other distribution other than cash dividends out of retained
earnings, or any right to subscribe for or purchase any shares of stock of any
class or any other securities, or to receive any other right, or (b) there is
any capital reorganization of the Company, any reclassification of the capital
stock of the Company, any consolidation or merger of the Company with or into
another entity, or any conveyance of all or substantially all of the assets of
the Company, or (c) there is any voluntary dissolution, liquidation or
winding-up of the Company, the Company will mail to the Holder a notice
specifying, as the case may be, (i) the record date for the purpose of such
dividend, distribution or right, and the amount and character of such dividend,
distribution or right, or (ii) the date on which such reorganization,
reclassification, consolidation, merger, conveyance, dissolution, liquidation or
winding-up is to take place, and the time, if any, that is to be fixed, as of
which the holders of record of Common Stock (or such stock or securities at the
time receivable upon the exercise of this Warrant) shall be entitled to exchange
their shares of Common Stock (or such other stock or securities) for securities
or other property deliverable upon such reorganization, reclassification,
consolidation, merger, conveyance, dissolution, liquidation or winding-up. Such
notice shall be mailed at least fourteen (14) days prior to the date therein
specified.

ARTICLE 8. Amendments. This Warrant may not be amended without the prior written
consent of the Holder.

ARTICLE 9. Notices. Any notice, certificate or other communication which is
required or convenient under the terms of this Warrant shall be duly given if it
is in writing and delivered in person or mailed by first class mail, postage
prepaid, and directed to the Holder of the Warrant at its address as it appears
on the Register or if to the Company to its principal executive offices. The
time when such notice is sent shall be the time of the giving of the notice.

ARTICLE 10. Time. Where this Warrant provides for a payment or performance on a
Saturday or Sunday or a public holiday in the State of Ohio, such payment or
performance may be made on the next succeeding business day, without liability
of the Company for interest on any such payment.

ARTICLE 11. Rules of Construction. In this Warrant, unless the context otherwise
requires, words in the singular number include the plural, and in the plural
include the singular, and words of the masculine gender include the feminine and
the neuter, and when the sense so indicates, words of the neuter gender may
refer to any gender. The numbers and titles of sections contained in this
Warrant are inserted for convenience of reference only, and they neither form a
part of this Warrant nor are to be used in the construction or interpretation
hereof.

ARTICLE 12. Governing Law. The validity, terms, performance and enforcement of
this Warrant shall be governed by those laws of the State of Ohio that are
applicable to agreements that are negotiated, executed, delivered and performed
solely in the State of Ohio.

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         IN WITNESS WHEREOF, NEOPROBE CORPORATION has caused this Warrant to be
executed by its officer thereto duly authorized.

                                            NEOPROBE CORPORATION

                                            By
                                              ----------------------------------
                                            Name:  David C. Bupp
                                            Title:  President


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                              ASSIGNMENT OF WARRANT

The undersigned hereby sell(s) and assign(s) and transfer(s) unto_______________


________________________________________________________________________________
                   (name, address and SSN or EIN of assignee)


_______________________________________________________of this Warrant.
                 (portion of Warrant)




Date:________________________________    Sign:__________________________________
                                              (Signature must conform in all 
                                              respects to name of Holder shown 
                                              on face of Warrant)

Signature Guaranteed:


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                               NOTICE OF EXERCISE

           [TO BE COMPLETED AND SIGNED ONLY UPON EXERCISE OF WARRANT]

         The undersigned, the Holder of this Warrant, hereby irrevocably elects
to exercise the right to purchase Common Stock, par value $.001 per share, of
Neoprobe Corporation.



                                         


                                           ------------------------------------------------------------
                                                      (whole number of Warrants exercised)

                                            
[Signature must be guaranteed if name of   ------------------------------------------------------------
holder of shares differs from registered           (name of holder of shares if different than
Holder of Warrant]                                             Holder of Warrant)

                                           ------------------------------------------------------------
                                                   (address of holder of shares if different than
                                                               Holder of Warrant)

                                           ------------------------------------------------------------
                                                 (Social Security or EIN of holder of shares if
                                                         different than Holder of Warrant)

Date:                                       Sign:
     -----------------------------------         ------------------------------------------------------
                                                 (Signature must conform in all respects to name of
                                                 Holder shown on face of Warrant)


Signature Guaranteed:


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