Exhibit
        10.4

       

      REGISTRATION
        RIGHTS AGREEMENT

       

      THIS
        REGISTRATION RIGHTS AGREEMENT (“Agreement”)
        is
        made July 3, 2007, by and among
        Neoprobe
        Corporation, a Delaware corporation (the “Company”),
        David
        C. Bupp, residing at 9095 Moors Place North, Dublin, Ohio 43017, Cynthia
        B.
        Gochoco, residing at 1550 Chapel Drive, York, Pennsylvania 17404, and Walter
        H.
        Bupp, residing at 2038 Wyntre Brook Drive, York, Pennsylvania 17403, as joint
        tenants with right of survivorship (each an “Investor”
and
        collectively “Investors”).

       

      Recitals

       

      A.
        The
        Company and the Investors are parties to the 10% Convertible Note Purchase
        Agreement, dated July 3, 2007 (the “Purchase
        Agreement”),
        whereby Investors have purchased the Company’s 10% Convertible Note, due July 8,
        2008 (the “Note”),
        and a
        warrant to purchase a total of 500,000 shares of the Company’s Common Stock (the
“Warrant”).

       

      B.
        In
        order to induce the Company to enter into the Purchase Agreement and to induce
        Investors to purchase the Note and Warrant pursuant to the Purchase Agreement,
        Investors and the Company hereby agree that this Agreement shall govern the
        rights of Investors or any permitted assignee to cause the Company to register
        Common Stock issuable to Investors on conversion of the Note (the “Conversion
        Shares”)
        and
        upon exercise of the Warrant (“Warrant
        Shares”).

       

      Statement
        of Agreement

       

      In
        consideration of the mutual covenants contained herein and the consummation
        of
        the sale and purchase of the Note and Warrant pursuant to the Purchase
        Agreement, and for other good and valuable consideration, the receipt and
        sufficiency of which are hereby acknowledged, the parties hereto, intending
        to
        be legally bound hereby, agree as follows:

       

      1. Definitions. For
        purposes of this Agreement:

       

      (a) “Commission”
shall
        mean the Securities and Exchange Commission, or any other federal agency
        at the
        time administering the Securities Act

       

      (b) “Common
        Stock”
means
        (a) the Company’s common stock, $.001 par value, as authorized on the date of
        this Agreement, and (b) any other securities into which or for which any
        of the
        securities described in (a) may be converted or exchanged pursuant to a plan
        of
        recapitalization, reorganization, merger, sale of assets or
        otherwise.

       

      (c) “Exchange
        Act”
means
        the Securities Exchange Act of 1934, as amended, and the rules and regulations
        promulgated thereunder.

       

      
        
           

        

        
          1

          
            

          

        

        
           

        

      

       

      
        (d) “Holder”
means
          any holder of outstanding Registrable Securities or anyone who holds outstanding
          Registrable Securities to whom the registration rights conferred by this
          Agreement have been transferred in compliance with this Agreement.

         

        (e) “Initiating
          Holders”
means,
          collectively, Holders of at least fifty-one percent (51%) of the Registrable
          Securities then outstanding.

         

        (f) “Person”
means
          any individual, corporation, partnership, trust, limited liability company,
          association or other
          entity.

         

        (g) “Register,”
          “registered”
and
          “registration”
means
          a
          registration effected by preparing and filing a registration statement
          in
          compliance with the Securities Act, and the declaration or ordering of
          the
          effectiveness of such registration statement, and compliance with applicable
          state securities laws of such states in which Holders notify the Company
          of
          their intention to offer Registrable Securities.

         

        (h) “Registrable
          Securities”
means
          all of the following (i) any and all Conversion Shares and Warrant Shares;
          (ii)
          stock issued in respect of stock referred to in clause (i) of this paragraph
          in
          any reorganization; or (iii) stock issued in respect of the stock referred
          to in
          clauses (i) or (ii) or this paragraph as a result of a stock split, stock
          dividend, recapitalization or combination. Notwithstanding the foregoing,
          Registrable Securities shall not include otherwise Registrable Securities
          (x)
          sold by a Person in a transaction in which his rights under this Agreement
          are
          not properly assigned; or (y) (A) sold to or through a broker or dealer
          or
          underwriter in a public distribution or a public securities transaction
          that is
          either registered under the Securities Act or is exempt from registration,
          or
          (B) sold in a transaction exempt from the registration and prospectus delivery
          requirements of the Securities Act under Section 4(1) thereof so that all
          transfer restrictions, and restrictive legends with respect thereto, if
          any, are
          removed upon the consummation of such sale, or (C) the registration rights
          associated with such securities have been terminated pursuant to Section
          13 of
          this Agreement.

         

        (i) “Rule
          144”
means
          Rule 144 promulgated by the Commission under the Securities Act.

         

        (j) “Securities
          Act”
means
          the Securities Act of 1933, as amended, and the rules and regulations
          promulgated thereunder.

         

        2. Demand
          Registration.
           

         

        (a)
          If
          the Company shall receive from Initiating Holders a written request that
          the
          Company effect any registration with respect to all or at least 50% in
          the
          aggregate of the issued and outstanding Registrable Securities held by
          Initiating Holders, the Company shall: 

         

           (i)
          promptly give written notice of the proposed registration to all other
          Holders;
          and

         

           (ii)
          as
          soon as practicable use its reasonable best efforts to register (including,
          without limitation, the execution of an undertaking to file post-effective
          amendments and any other governmental requirements) all Registrable Securities
          which the Holders request to be registered; provided,
          however,
          that the
          Company shall not be obligated to file a registration statement pursuant
          to this
          Section 2:

         

           (A)
          prior
          to September 31, 2007;

         

        
          
             

          

          
            2

            
              

            

          

          
             

          

        


           (B)
          within 120 days following the effective date of any registered offering
          of the
          Company’s securities to the general public in which the Holders of Registrable
          Securities shall have been able effectively to register all Registrable
          Securities as to which registration shall have been requested;

         

           (C)
          in
          any registration having an aggregate offering price (before deduction of
          underwriting discounts and expenses of sale) of less than $1,000,000; or
          

         

           (D)
          after
          the Company has effected one such registration pursuant to this Section
          2 and
          such registration has been declared or ordered effective, and the full
          number of
          Registrable Securities for which registration has been requested have been
          included in the registration.   

         

        Subject
          to the foregoing clauses (A) through (D), the Company shall file a registration
          statement covering the Registrable Securities so requested to be registered
          as
          soon as practicable, but in any event within ninety (90) days after receipt
          of
          the request or requests of the Initiating Holders and shall use reasonable
          best
          efforts to have such registration statement promptly declared effective
          by the
          Commission; provided,
          however,
          that if
          the Company shall furnish to such Holders a certificate signed by the Chairman
          of the Board of Directors of the Company stating that in the good faith
          judgment
          of the Board of Directors, with advice of counsel, it would be seriously
          detrimental to the Company and its stockholders for such registration statement
          to be filed within such ninety-day (90-day) period and it is therefore
          essential
          to defer the filing of such registration statement, the Company shall have
          an
          additional period of not more than ninety (90) days after the expiration
          of the
          initial ninety-day (90-day) period within which to file such registration
          statement; provided, that during such time the Company may not file a
          registration statement for securities to be issued and sold for its own
          or
          anyone else’s account; and further
          provided,
          that
          during such deferment, the Initiating Holders may elect not to pursue such
          registration request, in which event, upon giving notice to the Company
          of such
          decision prior to the declaration of effectiveness of any such registration
          statement, the Initiating Holders shall not be deemed to have availed themselves
          of the demand registration right herein provided for.  

         

        (b)
          If
          the Initiating Holders intend to distribute the Registrable Securities
          covered
          by their request by means of an underwriting, they shall so advise the
          Company
          as a part of their request. In such event, the Company shall include such
          information in the written notice referred to in Section 2(a)(i). In either
          such
          event, if so requested in writing by the Company, the Initiating Holders
          shall
          negotiate with an underwriter selected by the Company with regard to the
          underwriting of such requested registration; provided,
          however,
          that if
          a majority in interest of the Initiating Holders have not agreed with such
          underwriter as to the terms and conditions of such underwriting within
          twenty
          (20) days following commencement of such negotiations, a majority in interest
          of
          the Initiating Holders may select an underwriter of their choice. The right
          of
          any Holder to registration pursuant to Section 2 shall be conditioned upon
          such
          Holder’s participation in such underwriting. The Company shall (together with
          all Holders proposing to distribute their securities through such underwriting)
          enter into an underwriting agreement in customary form with the underwriter
          or
          underwriters selected for such underwriting. Notwithstanding any other
          provision
          of this Section 2, if the managing underwriter advises the Initiating Holders
          in
          writing that marketing factors require a limitation of the number of shares
          to
          be underwritten, the Company shall so advise all Holders, and the number
          of
          shares of Registrable Securities that may be included in the registration
          and
          underwriting shall be allocated among all Holders thereof in proportion,
          as
          nearly as practicable, to the respective amounts of Registrable Securities
          held
          by such Holders; provided,
          however, that
          securities to be included in such registration statement as a result of
          piggyback registration rights as well as any securities to be offered by
          the
          Company, its officers and employees shall be excluded from the registration
          statement prior to the exclusion of any Registrable Securities held by
          the
          Holders. If any Holder disapproves of the terms of the underwriting, such
          Holder
          may elect to withdraw therefrom by written notice to the Company, the managing
          underwriter and the Initiating Holders. If, by the withdrawal of such
          Registrable Securities, a greater number of Registrable Securities held
          by other
          Holders may be included in such registration (up to the limit imposed by
          the
          underwriters) the Company shall offer to all Holders who have included
          Registrable Securities in the registration the right to include additional
          Registrable Securities in the same proportion used in determining the limitation
          as set forth above. Any Registrable Securities which are excluded from
          the
          underwriting by reason of the underwriter’s marketing limitation or withdrawn
          from such underwriting shall be withdrawn from such registration.

         

        
          
             

          

          
            3

            
              

            

          

          
             

          

        


        3. Piggyback
          Registration.
           

         

        (a)
          If at
          any time or from time to time, the Company shall determine to register
          any of
          its securities, for its own account or the account of any of its stockholders,
          other than a registration pursuant to Section 2 or Section 4, a registration
          relating solely to employee benefit plans, a registration relating solely
          to an
          SEC Rule 145 transaction, a transaction relating solely to the sale of
          debt or
          convertible debt instruments, or a post-effective amendment to any registration
          statement that became effective prior to the date of the Purchase Agreement,
          or
          a new registration statement that relates to the same securities that were
          the
          subject of such previously effective registration statement, the Company
          will:
  

         

        (i)
          give
          to each Holder written notice thereof as soon as practicable prior to filing
          the
          registration statement; and 

         

           (ii)
          include in such registration and in any underwriting involved therein,
          all the
          Registrable Securities specified in a written request or requests, made
          within
          fifteen (15) days after receipt of such written notice from the Company,
          by any
          Holder or Holders, except as set forth in subsection (b) below.  

         

        (b)
          If
          the registration is for a registered public offering involving an underwriting,
          the Company shall so advise the Holders as a part of the written notice
          given
          pursuant to Section 3(a)(i). In such event, the right of any Holder to
          registration pursuant to Section 3 shall be conditioned upon such Holder’s
          participation in such underwriting. All Holders proposing to distribute
          their
          securities through such underwriting shall (together with the Company and
          the
          other holders distributing their securities through such underwriting)
          enter
          into an underwriting agreement in customary form with the underwriter or
          underwriters selected for such underwriting by the Company. Notwithstanding
          any
          other provision of this Section 3, if the managing underwriter determines
          that
          marketing factors require a limitation of the number of shares to be
          underwritten, the managing underwriter may limit the number of Registrable
          Securities to be included in the registration and underwriting, or may
          exclude
          Registrable Securities entirely from such registration if the registration
          is
          the first registered offering for the sale of the Company’s securities to the
          general public (provided that there is first excluded from such registration
          and
          underwriting all shares held by officers, directors or employees of the
          Company
          or any subsidiary, any holder thereof not having any such contractual incidental
          registration rights and any holder having contractual, incidental registration
          rights subordinate and junior to the rights of the Holders of Registrable
          Securities). The Company shall so advise all Holders and the other holders
          distributing their securities through such underwriting pursuant to piggyback
          registration rights similar to this Section 3, and the number of shares
          of
          Registrable Securities and other securities that may be included in the
          registration and underwriting shall be allocated among all Holders and
          other
          holders (subject to the limitations set forth above) in proportion, as
          nearly as
          practicable, to the respective amounts of Registrable Securities held by
          such
          Holders and other securities held by other holders at the time of filing
          the
          registration statement. If any Holder disapproves of the terms of any such
          underwriting, such Holder may elect to withdraw therefrom by written notice
          to
          the Company and the managing underwriter. If, by the withdrawal of such
          Registrable Securities, a greater number of Registrable Securities held
          by other
          Holders may be included in such registration (up to the limit imposed by
          the
          underwriters), the Company shall offer to all Holders who have included
          Registrable Securities in the registration the right to include additional
          Registrable Securities. Any Registrable Securities excluded or withdrawn
          from
          such underwriting shall be withdrawn from such registration. 

         

        
          
             

          

          
            4

            
              

            

          

          
             

          

        

         

        4. Form
          S-3.
          

         

        (a)
          From
          and after such time as Form S-3 is available to the Company for the registration
          of secondary offerings for the account of any person other than the issuer,
          Holders shall have the right at any time to request registrations on Form
          S-3
          (or any similar form), provided that such requests shall be in writing
          and shall
          state the number of shares of Registrable Securities to be disposed of
          and the
          intended method of disposition of shares by such Holders. As soon as
          practicable, the Company will file such registration statement and use
          its
          reasonable best efforts to have such registration statement declared effective,
          provided,
          however,
          that the
          Company shall not be obligated to effect such registration:

         

        (i)
          within ninety (90) days of the effective date of any registration referred
          to in
          Sections 2 and 3 above;   

         

        (ii)
          unless the Holder or Holders requesting registration propose to dispose
          of
          shares of Registrable Securities at an aggregate price to the public (before
          deduction of underwriting discounts and expenses of sale) of at least $250,000.
            

         

        (iii)
          if
          the Company shall furnish to the Holders a certificate signed by the Chairman
          of
          the Board of Directors of the Company stating that in the good faith and
          reasonable judgment of the Board of Directors of the Company, with advice
          of
          counsel, it would be seriously detrimental to the Company and its stockholders
          for such Form S- 3 registration to be effected at such time, in which event
          the
          Company shall have the right to defer the filing of the Form S-3 registration
          statement for a period of not more than sixty (60) days after receipt of
          the
          request of the Holder or Holders under this Section 2.3; provided, that
          such
          right to delay a request shall be exercised by the Company not more than
          once in
          any twelve (12) month period; or


        (iv)
          if
          the Company has been required to file two registration statements pursuant
          to
          this Section 4 within the twelve-month period preceding the
          request.

         

        
          
             

          

          
            5

            
              

            

          

          
             

          

        

         

        (b)
          The
          Company shall give written notice to all Holders of Registrable Securities
          of
          the receipt of a request for registration pursuant to this Section 4 and
          shall
          provide a reasonable opportunity for other Holders to participate in the
          registration; provided,
          however,
          that if
          the registration is for an underwritten offering, the following terms shall
          apply to all participants in such offering: The right of any Holder to
          registration pursuant to Section 4 shall be conditioned upon such Holder’s
          participation in such underwriting. All Holders proposing to distribute
          their
          securities through such underwriting shall (together with the Company and
          the
          other Holders distributing their securities through such underwriting)
          enter
          into an underwriting agreement in customary form with the underwriter or
          underwriters selected for such underwriting by the Company. Notwithstanding
          any
          other provision of this Section 4, if the managing underwriter determines
          that
          marketing factors require a limitation of the number of shares to be
          underwritten, the managing underwriter may limit the number of Registrable
          Securities to be included in the registration and underwriting. The Company
          shall so advise all Holders of Registrable Securities which would otherwise
          be
          registered and underwritten pursuant hereto, and the number of shares of
          Registrable Securities that may be included in the registration and underwriting
          shall be allocated among the Holders in proportion, as nearly as practicable,
          to
          the respective amounts of securities requested by such Holders to be included
          in
          such registration. If any Holder disapproves of the terms of any such
          underwriting, he may elect to withdraw therefrom by written notice to the
          Company and the underwriter. If, by the withdrawal of such Registrable
          Securities, a greater number of Registrable Securities held by other Holders
          may
          be included in such registration (up to the limit imposed by the underwriters),
          the Company shall offer to all Holders who have included Registrable Securities
          in the registration the right to include additional Registrable Securities
          in
          the same proportion used in determining the limitation as set forth above.
          Any
          Registrable Securities excluded or withdrawn from such underwriting shall
          be
          withdrawn from such registration. Subject to the foregoing, the Company
          will use
          its reasonable best efforts to effect promptly the registration of all
          shares of
          Registrable Securities on Form S-3 to the extent requested by the Holder
          or
          Holders thereof for purposes of disposition. 

         

        5. Expenses
          of Registration.
           In
          addition to the fees and expenses contemplated by Section 6 hereof, all
          expenses
          incurred in connection with one registration pursuant to Section 2 hereof
          and
          all registrations pursuant to Sections 3 and 4 hereof, including without
          limitation all Securities
          and Exchange Commission and National Association of Securities Dealers,
          Inc.
          registration, filing and qualification fees and expenses, “blue-sky” fees and
          expenses, printing expenses, transfer agent fees and expenses, and fees
          and
          disbursements of counsel for the Company and a single counsel for all Holders,
          and expenses of any special audits of the Company’s financial statements
          incidental to or required by such registration, shall be borne by the Company,
          except that the Company shall not be required to pay underwriters’ fees,
          discounts or commissions relating to Registrable Securities or fees of
          a
          separate legal counsel of a Holder other than the counsel described above.
          

         

        
          
             

          

          
            6

            
              

            

          

          
             

          

        


        6. Registration
          Procedures.
          In the
          case of each registration effected by the Company pursuant to this Agreement,
          the Company will keep each Holder participating therein advised in writing
          as to
          the initiation of each registration and as to the completion thereof. At
          its
          expense the Company will:   

         

        (a)
          keep
          such registration pursuant to Sections 2, 3 and 4 continuously effective
          for
          periods of one hundred twenty (120), ninety (90) and ninety (90) days,
          respectively, or, in each case, such reasonable period necessary to permit
          the
          Holder or Holders to complete the distribution described in the registration
          statement relating thereto, whichever first occurs, provided,
          however,
          that in
          any registration pursuant to Section 3 the registration as to the Registrable
          Securities included therein shall remain effective for the period of
          effectiveness of the registration statement if greater than 90
          days;

         

           (b)
          promptly prepare and file with the Commission such amendments and supplements
          to
          such registration statement and the prospectus used in connection therewith
          as
          may be necessary to comply with the provisions of the Securities Act, and
          to
          keep such registration statement effective for that period of time specified
          in
          Section 6(a) above;

         

        (c)
          permit the Holder or Holders to review and comment upon the registration
          statement and all amendments and supplements thereto at least two Business
          Days
          prior to their filing with the Commission;

         

        (d)
          furnish the Holder or Holders (i) promptly after the same is prepared and
          filed
          with the Commission, at least one copy of the registration statement and
          any
          amendment(s) thereto, including financial statements and schedules, and
          all
          exhibits, and (ii) upon the effectiveness of any registration statement,
          one
          copy of the prospectus included in such registration statement and all
          amendments and supplements thereto (or such other number of copies as the
          Holder
          or Holders may reasonably request);

         

           (e)
          furnish such number of prospectuses and other documents incident thereto
          as a
          Holder from time to time may reasonably request; 

         

           (f)
          use
          reasonable best efforts to obtain the withdrawal of any order suspending
          the
          effectiveness of a registration statement, or the lifting of any suspension
          of
          the qualification of any of the Registrable Securities for sale in any
          jurisdiction, at the earliest possible moment;

         

           (g)
          register or qualify such Registrable Securities for offer and sale under
          the
          securities or blue sky laws of such jurisdictions as any Holder or underwriter
          reasonably requires, and keep such registration or qualification effective
          during the period set forth in Section 6(a) above;  provided;
          however, that
          the
          Company shall not be obligated to qualify to do business in any jurisdiction
          where it is not then so qualified or to take any action which would subject
          it
          to the service of process in suits other than those arising out of the
          offer or
          sale of the securities covered by the registration statement in any jurisdiction
          where it is not then so subject

         

        
          
             

          

          
            7

            
              

            

          

          
             

          

        

         

           (h)
          cause
          all Registrable Securities covered by such registrations to be listed on
          each
          securities exchange, on which similar securities issued by the Company
          are then
          listed or, if no such listing exists, use reasonable best efforts to list
          all
          Registrable Securities on one of the New York Stock Exchange, the American
          Stock
          Exchange or the Nasdaq Stock Market; 


        (i)
          cause
          its accountants to issue to the underwriter, if any, or the Holders, if
          there is
          no underwriter, comfort letters and updates thereof, in customary form
          and
          covering matters of the type customarily covered in such letters with respect
          to
          underwritten offerings; 

         

           (j)
          enter
          into such customary agreements (including underwriting agreements in customary
          form) and take all such other actions as the holders of a majority of the
          Registrable Securities being sold or the underwriters, if any, reasonably,
          request in order to expedite or facilitate the disposition of such Registrable
          Securities (including, without limitation, effecting a stock split or a
          combination of shares);   

         

        (k)
          make
          available for inspection by any seller of Registrable Securities, any
          underwriter participating in any disposition pursuant to such registration
          statement, and any attorney, accountant or other agent retained by any
          such
          seller or underwriter, all financial and other records, pertinent corporate
          documents and properties of the Company, and cause the Company's officers,
          directors, employees and independent accountants to supply all information
          reasonably requested by any such seller, underwriter, attorney, accountant
          or
          agent in connection with such registration statement;  

         

        (l)
          if
          the offering is underwritten, at the request of any Holder of Registrable
          Securities to furnish on the date that Registrable Securities are delivered
          to
          the underwriters for sale pursuant to such registration: (i) an opinion
          dated
          such date of counsel representing the Company for the purposes of such
          registration, addressed to the underwriters and to such Holder, stating
          that
          such registration statement has become effective under the Securities Act
          and
          that (A) to the best knowledge of such counsel, no stop order suspending
          the
          effectiveness thereof has been issued and no proceedings for that purpose
          have
          been instituted or are pending or contemplated under the Securities Act,
          (B) the
          registration statement, the related prospectus and each amendment or supplement
          thereof comply as to form in all material respects with the requirements
          of the
          Securities Act (except that such counsel need not express any opinion as
          to
          financial statements or other financial data contained therein), and (C)
          to such
          other effects as reasonably may be requested by counsel for the underwriters
          or
          by such Holder or its counsel; and (ii) a letter dated such date from the
          independent public accountants retained by the Company, addressed to the
          underwriters and to such seller, stating that they are independent public
          accountants within the meaning of the Securities Act and that, in the opinion
          of
          such accountants, the financial statements of the Company included in the
          registration statement or the prospectus, or any amendment or supplement
          thereof, comply as to form in all material respects with the applicable
          accounting requirements of the Securities Act, and such letter shall
          additionally cover such other financial matters (including information
          as to the
          period ending no more than five business days prior to the date of such
          letter)
          with respect to such registration as such underwriters or such seller reasonably
          may request;  

         

        (m)
          notify each Holder, at any time a prospectus covered by such registration
          statement is required to be delivered under the Securities Act, of the
          happening
          of any event of which it has knowledge as a result of which the prospectus
          included in such registration statement, as then in effect, includes an
          untrue
          statement of a material fact or omits to state a material fact required
          to be
          stated therein or necessary to make the statements therein not misleading
          in the
          light of the circumstances then existing;

         

        
          
             

          

          
            8

            
              

            

          

          
             

          

        

         

        (n)
          use
          its reasonable efforts to insure the obtaining of all necessary approvals
          from
          the National Association of Securities Dealers, Inc.; and 

         

        (o)
          otherwise use its reasonable efforts to comply with all applicable rules
          and
          regulations of the Commission.   

         

        7. Indemnification.
            

         

        (a)
          In
          the event of a registration of any of the Registrable Securities under
          the
          Securities Act pursuant to Sections 2, 3 or 4, the Company will indemnify
          and
          hold harmless each Holder of such Registrable Securities (including their
          officers, directors, affiliates, members, partners and managers) thereunder,
          each underwriter of such Registrable Securities thereunder and each other
          Person, if any, who controls such Holder or underwriter within the meaning
          of
          the Securities Act, against any losses, claims, damages or liabilities,
          joint or
          several, to which such Holder, underwriter or controlling person may become
          subject under the Securities Act or otherwise, insofar as such losses,
          claims,
          damages or liabilities (or actions in respect thereof) arise out of or
          are based
          upon any untrue statement or alleged untrue statement of any material fact
          contained in any registration statement under which such Registrable Securities
          were registered under the Securities Act or any filing with any state securities
          commission or agency, any preliminary or amended prospectus or final prospectus
          contained therein, or any amendment or supplement thereof, or arise out
          of or
          are based upon the omission or alleged omission to state therein a material
          fact
          required to be stated therein or necessary to make the statements therein
          not
          misleading, or any violation by the Company of any rule or regulation
          promulgated under the Securities Act or any state securities law or regulation
          applicable to the Company and relating to action or inaction required of
          the
          Company in connection with any such registration, and will reimburse each
          such
          Holder, each of its officers, directors and partners, and each person
          controlling such Holder, each such underwriter and each person who controls
          any
          such underwriter, for any reasonable legal and any other expenses incurred
          in
          connection with investigating, defending or settling any such claim, loss,
          damage, liability or action, provided that the Company will not be liable
          in any
          such case to the extent that any such claim, loss, damage or liability
          arises
          out of or is based on any untrue statement or omission based upon written
          information furnished to the Company by an instrument duly executed by
          such
          Holder or underwriter specifically for use therein. 


        (b)
          Each
          Holder will, if Registrable Securities held by or issuable to such Holder
          are
          included in the securities as to which such registration is being effected,
          indemnify and hold harmless the Company, each of its directors and officers,
          each underwriter, if any, of the Company’s securities covered by such a
          registration statement, each person who controls the Company and each
          underwriter within the meaning of the Securities Act, and each other such
          Holder, each of its officers, directors, affiliates, members, partners
          and
          managers, and each person controlling such Holder, against all claims,
          losses,
          expenses, damages and liabilities (or actions in respect thereof) arising
          out of
          or based on any untrue statement (or alleged untrue statement) of a material
          fact contained in any such registration statement, prospectus, offering
          circular
          or other document, or any omission (or alleged omission) to state therein
          a
          material fact required to be stated therein or necessary to make the statements
          therein not misleading, and will reimburse the Company, such Holders, such
          directors, officers, partners, persons or underwriters for any reasonable
          legal
          or any other expenses incurred in connection with investigating, defending
          or
          settling any such claim, loss, damage, liability or action, in each case
          to the
          extent, but only to the extent, that such untrue statement (or alleged
          untrue
          statement) or omission (or alleged omission) is made in such registration
          statement, prospectus, offering circular or other document in reliance
          upon and
          in conformity with written information furnished to the Company by an instrument
          duly executed by such Holder specifically for use therein; provided, however,
          the total amount for which any Holder, its officers, directors, affiliates,
          members, partners and managers, and any person controlling such Holder,
          shall be
          liable under this Section 7(b) shall not in any event exceed the aggregate
          proceeds received by such Holder from the sale of Registrable Securities
          sold by
          such Holder in such registration. 

         

        
          
             

          

          
            9

            
              

            

          

          
             

          

        

         

           (c)
          Each
          party entitled to indemnification under this Section 7 (the “Indemnified
          Party”)
          shall
          give notice to the party required to provide indemnification (the “Indemnifying
          Party”)
          promptly after such Indemnified Party has actual knowledge of any claims
          as to
          which indemnity may be sought, and shall permit the Indemnifying Party
          to assume
          the defense of any such claim or any litigation resulting therefrom, provided
          that counsel for the Indemnifying Party, who shall conduct the defense
          of such
          claim or litigation, shall be approved by the Indemnified Party (whose
          approval
          shall not be unreasonably withheld), and the Indemnified Party may participate
          in such defense at such party’s expense, and provided further that the failure
          of any Indemnified Party to give notice as provided herein shall not relieve
          the
          Indemnifying Party of its obligations hereunder, but such failure shall
          so
          relieve the Indemnifying Party to
          the
          extent that such failure materially prejudices the Indemnifying Party’s ability
          to defend such claim or litigation.
          No
          Indemnifying Party, in the defense of any such claim or litigation, shall,
          except with the consent of each Indemnified Party, consent to entry of
          any
          judgment or enter into any settlement which does not include as an unconditional
          term thereof the giving by the claimant or plaintiff to such Indemnified
          Party
          of a release from all liability in respect of such claim or litigation.
           

         

        (d) Notwithstanding
          anything else herein to the contrary, the
          foregoing indemnity agreements of the Company and the selling Holders are
          subject to the condition that, insofar as they relate to any damages arising
          from any untrue statement or alleged untrue statement of a material fact
          contained in, or omission or alleged omission of a material fact from,
          a
          preliminary prospectus (or necessary to make the statements therein not
          misleading) that has been corrected in the form of prospectus included
          in the
          registration statement at the time it becomes effective, or any amendment
          or
          supplement thereto filed with the Commission pursuant to Rule 424(b) under
          the
          Securities Act, such indemnity agreement shall not inure to the benefit
          of any
          Person if a copy of such prospectus was furnished to the Indemnified Party
          and
          such Indemnified Party failed to deliver, at or before the confirmation
          of the
          sale of the shares registered in such offering, a copy of such prospectus
          to the
          Person asserting the loss, liability, claim, or damage in any case in which
          such
          delivery was required by the Securities Act.

         

        (e)
          Notwithstanding the foregoing, to the extent that the provisions on
          indemnification contained in the underwriting agreements entered into among
          the
          selling Holders, the Company and the underwriters in connection with the
          underwritten public offering are in conflict with the foregoing provisions,
          the
          provisions in the underwriting agreement shall be controlling as to the
          Registrable Securities included in the public offering.  

         

        
          
             

          

          
            10

            
              

            

          

          
             

          

        


        (f)
          If
          the indemnification provided for in this Section 7 is held by a court of
          competent jurisdiction to be unavailable to an Indemnified Party with respect
          to
          any loss, liability, claim, damage or expense referred to therein, to
          provide for just and equitable contribution to joint liability under the
          Securities Act, the
          Indemnifying Party, in lieu of indemnifying such Indemnified Party thereunder,
          shall contribute to the amount paid or payable by such Indemnified Party
          as a
          result of such loss, liability, claim, damage or expense in such proportion
          as
          is appropriate to reflect the relative fault of the Indemnifying Party
          on the
          one hand and of the indemnified party on the other hand in connection with
          the
          statements or omissions which resulted in such loss, liability, claim,
          damage or
          expense as well as any other relevant equitable considerations. The relevant
          fault of the Indemnifying Party and the Indemnified Party shall be determined
          by
          reference to, among other things, whether the untrue or alleged untrue
          statement
          of a material fact or the omission to state a material fact relates to
          information supplied by the Indemnifying Party or by the Indemnified Party
          and
          the parties' relative intent, knowledge, access to information and opportunity
          to correct or prevent such statement or omission. Notwithstanding the foregoing,
          the amount any Holder shall be obligated to contribute pursuant to this
          Section
          7(f) shall be limited to an amount equal to the proceeds to such Holder
          of the
          Registrable Securities sold pursuant to the registration statement which
          gives
          rise to such obligation to contribute (less the aggregate amount of any
          damages
          which the Holder has otherwise been required to pay in respect of such
          loss,
          claim, damage, liability or action or any substantially similar loss, claim,
          damage, liability or action arising from the sale of such Registrable
          Securities). No person or entity guilty of fraudulent misrepresentation
          (within
          the meaning of Section 11(f) of the Securities Act) will be entitled to
          contribution from any person or entity that was not guilty of such fraudulent
          misrepresentation.  

         

        (g)
          The
          indemnification provided by this Section 7 shall be a continuing right
          to
          indemnification and shall survive the registration and sale of any securities
          by
          any Person entitled to indemnification hereunder and the expiration or
          termination of this Agreement. 

         

        8. Lock
          Up Agreement.
           In
          consideration for the Company agreeing to its obligations under this Agreement,
          each Holder agrees in connection with any registration of the Company’s
          securities (whether or not such Holder is participating in such registration)
          upon the request of the Company and the underwriters managing any underwritten
          offering of the Company’s securities, not to sell, make any short sale of, loan,
          grant any option for the purchase of, or otherwise dispose of any Registrable
          Securities (other than those included in the registration) without the
          prior
          written consent of the Company or such underwriters, as the case may be,
          for
          such period of time (not to exceed 90 days) from the effective date of
          such
          registration as the Company and the underwriters may specify, so long as
          all
          Holders, Persons participating in such registration (other than as to shares
          that are included in the registration statement), stockholders holding
          more than
          one percent (1%) of the outstanding Common Stock and all officers and directors
          of the Company are bound by a comparable obligation. The
          underwriters in connection with such registration
          are
          intended third-party beneficiaries of this Section 8
          and
          shall have the right, power, and authority to enforce the provisions hereof
          as
          though they were a party hereto.

         

        
          
             

          

          
            11

            
              

            

          

          
             

          

        


        9. Information
          From Holder: Suspension of Sales.
          The
          Holder or Holders of Registrable Securities included in any registration
          shall
          promptly furnish to the Company such information regarding such Holder
          or
          Holders and the distribution proposed by such Holder or Holders as the
          Company
          may reasonably request in writing and as shall be required in connection
          with
          any registration referred to herein. Each Holder shall suspend further
          sales
          pursuant to any registration statement upon receipt of a notice from the
          Company
          pursuant to Section 6(m) hereof, and the Company determines that it is
          necessary
          or advisable to amend or supplement the prospectus. The Company may suspend
          not
          more than twice in any twelve (12) months for not more than thirty (30)
          days

         

        10. Rule
          144 Reporting.
           With
          a
          view to making available to Holders of Registrable Securities the benefits
          of
          Rule 144, until the later of the date on which the Warrants have been fully
          exercised or have expired or the payment in full of the Note, the Company
          agrees
          to: (a) make and keep public information available, as those terms are
          understood and defined in Rule 144; (b) use its reasonable best efforts
          to file
          with the Commission in a timely manner all reports and other documents
          required
          of the Company under the Securities Act and the Exchange Act; and (c) furnish
          to
          each Holder of Registrable Securities upon request a written statement
          by the
          Company as to its compliance with
          the
          reporting requirements of Rule 144, the Securities Act, and the Exchange
          Act.
           

         

        11. Transfer
          of Registration Rights.
          The
          rights under this Agreement
          may
be assigned
          (but
          only
          with all related obligations)
          by
          a
          Holder to any permitted transferee of the Note or the Warrant.
          The
          terms and conditions of this Agreement inure to the benefit of and are
          binding
          upon the respective successors and permitted assignees of the parties.
          Nothing
          in this Agreement, express or implied, is intended to confer upon any party
          other than the parties hereto or their respective successors and permitted
          assignees any rights, remedies, obligations or liabilities under or by
          reason of
          this Agreement, except as expressly provided herein. 

         

        12. Termination
          of Registration Rights. The
          right
          of any Holder to request registration or inclusion of Registrable Securities
          in
          any registration pursuant to Sections
          2, 3 or 4
          shall
          terminate when
          all
          of such Holder’s Registrable Securities could be sold without restriction under
          SEC Rule 144(k).

         

        13. Miscellaneous. 

         

        (a)
          Successors
          and Assigns.
          The
          terms and conditions of this Agreement inure to the benefit of and are
          binding
          upon the respective successors and permitted assignees of the parties.
          Nothing
          in this Agreement, express or implied, is intended to confer upon any party
          other than the parties hereto or their respective successors and permitted
          assignees any rights, remedies, obligations or liabilities under or by
          reason of
          this Agreement, except as expressly provided herein.
          A Person
          is deemed to be a holder of Registrable Securities whenever such Person
          owns or
          is deemed to own of record such Registrable Securities. If the Company
          receives
          conflicting instructions, notices or elections from two or more Persons
          with
          respect to the same Registrable Securities, the Company shall act upon
          the basis
          of instructions, notice or election received from the registered owner
          of such
          Registrable Securities

         

        
          
             

          

          
            12

            
              

            

          

          
             

          

        


        (b)
          Governing
          Law.
          The
          corporate laws of the State of Delaware shall govern all issues concerning
          the
          relative rights of the Company and its stockholders. All other questions
          concerning the construction, validity, enforcement and interpretation of
          this
          Agreement shall be governed by the internal laws of the State of Ohio,
          without
          giving effect to any choice of law or conflict of law provision or rule
          (whether
          of the State of Ohio or any other jurisdictions) that would cause the
          application of the laws of any jurisdiction other than the State of Ohio.
          Each
          party hereby irrevocably waives personal service of process and consents
          to
          process being served in any such suit, action or proceeding by mailing
          a copy
          thereof to such party at the address for such notices to it under this
          Agreement
          and agrees that such service shall constitute good and sufficient service
          of
          process and notice thereof. Nothing contained herein shall be deemed to
          limit in
          any way any right to serve process in any manner permitted by law. If any
          provision of this Agreement shall be invalid or unenforceable in any
          jurisdiction, such invalidity or unenforceability shall not affect the
          validity
          or enforceability of the remainder of this Agreement in that jurisdiction
          or the
          validity or enforceability of any provision of this Agreement in any other
          jurisdiction.

         

        (c)
          Counterparts;
          Facsimile.
          This
          Agreement may be executed in two or more counterparts, each of which shall
          be
          deemed an original, but all of which together shall constitute one and
          the same
          instrument. This Agreement may also be executed and delivered by facsimile
          signature and in two or more counterparts, each of which shall be deemed
          an
          original, but all of which together shall constitute one and the same
          instrument.

         

        (d)
          Titles
          and Subtitles.
          The
          titles and subtitles used in this Agreement are for convenience only and
          are not
          to be considered in construing or interpreting this Agreement.

         

        (e)
          Notices.
          All
          notices and communications provided for hereunder shall be in writing and
          sent
          (i) by fax if the sender on the same day sends a confirming copy of such
          notice
          by a recognized overnight delivery service (charges prepaid), or (ii) by
          registered or certified mail with return receipt requested (postage prepaid),
          or
          (iii) by a recognized overnight delivery service (with charges prepaid).
          Any
          such notice must be sent:

        


        (A) if
          to the
          Company, to 

         

        Neoprobe
          Corporation 

        425
          Metro
          Place North, Suite 300

        Dublin,
          Ohio 43017 

        Attn:
          Chief Financial Officer

        (fax)
          (614) 793-9376

        


        copy
          to:

        


        William
          J. Kelly, Jr.

        Porter,
          Wright, Morris & Arthur

        41
          South
          High Street, Suite 2800

        Columbus,
          Ohio 43215

      

       

      
        
           

        

        
          13

          
            

          

        

        
           

        

      

      

        or
          to
          such other Person at such other place as the Company shall designate to
          Investors in writing;

        


        (B) if
          to
          Investors, to 

        


        David
          C.
          Bupp

        9095
          Moors Place North

        Dublin,
          Ohio 43017

        


        copy
          to:

        


        Kenneth
          J. Warren, Esq.

        5134
          Blazer Parkway

        Dublin,
          Ohio 43017

        


        or
          at
          such other address as Investors shall designate to the Company in writing;
          or

        


        (C) if
          to any
          permitted transferee or transferees of Investors, at such address or addresses
          as shall have been furnished to the Company at the time of the transfer
          or
          transfers, or at such other address or addresses as may have been furnished
          by
          such transferee or transferees to the Company in writing.

        


        (f)
          Amendments
          and Waivers.
          Any term
          of this Agreement may be amended and the observance of any term of this
          Agreement may be waived (either generally or in a particular instance,
          and
          either retroactively or prospectively) only with the written consent of
          the
          Company and the holders of a majority of the Registrable Securities then
          outstanding;
          and
          provided further that any provision hereof may be waived by any waiving
          party on
          such party’s own behalf, without the consent of any other party.
          Any
          amendment, termination, or waiver effected in accordance with this Section
          13(f)
          shall be binding on all parties hereto, regardless of whether any such
          party has
          consented thereto. No waivers of or exceptions to any term, condition,
          or
          provision of this Agreement, in any one or more instances, shall be deemed
          to be
          or construed as a further or continuing waiver of any such term, condition,
          or
          provision.

         

        (g)
          Severability.
          In case
          any one or more of the provisions contained in this Agreement is for any
          reason
          held to be invalid, illegal or unenforceable in any respect, such invalidity,
          illegality, or unenforceability shall not affect any other provision of
          this
          Agreement, and such invalid, illegal, or unenforceable provision shall
          be
          reformed and construed so that it will be valid, legal, and enforceable
          to the
          maximum extent permitted by law.

         

        (i)
          Entire
          Agreement.
          This
          Agreement, together with the Purchase Agreement, the Note and the Warrant,
          constitutes the full and entire understanding and agreement among
          the
          parties with respect to the subject matter hereof, and any other written
          or oral
          agreement relating to the subject matter hereof existing between the parties
          is
          expressly canceled. 

         

        
          
             

          

          
            14

            
              

            

          

          
             

          

        

         

        (j)
          Dispute
          Resolution.
          Any
          controversy, claim or dispute arising out of or relating to this Agreement
          or
          the breach, termination, enforceability or validity of this Agreement,
          including
          the determination of the scope or applicability of the agreement to arbitrate
          set forth in this Section 13(j) shall be determined exclusively by binding
          arbitration in the City of Columbus, Ohio. The arbitration shall be governed
          by
          the rules and procedures of the American Arbitration Association (the “AAA”)
          under its Commercial Arbitration Rules and its Supplementary Procedures
          for
          Large, Complex Disputes; provided that persons eligible to be selected
          as
          arbitrators shall be limited to attorneys-at-law each of whom (i) is on
          the
          AAA’s Large, Complex Case Panel or a Center for Public Resources (“CPR”) Panel
          of Distinguished Neutrals, or has professional credentials comparable to
          those
          of the attorneys listed on such AAA and CPR Panels and (ii) has actively
          practiced law (in private or corporate practice or as a member of the judiciary)
          for at least 15 years in the State of Ohio concentrating in either general
          commercial litigation or general corporate and commercial matters. Any
          arbitration proceeding shall be before one arbitrator mutually agreed to
          by the
          parties to such proceeding (who shall have the credentials set forth above)
          or,
          if the parties are unable to agree to the arbitrator within 15 business
          days of
          the initiation of the arbitration proceedings, then by the AAA. No provision
          of,
          nor the exercise of any rights under, this Section 13(j) shall limit the
          right
          of any party to request and obtain from a court of competent jurisdiction
          in the
          State of Ohio, County of Franklin (which shall have exclusive jurisdiction
          for
          purposes of this Section 13(j)) before, during or after the pendency of
          any
          arbitration, provisional or ancillary remedies and relief including injunctive
          or mandatory relief or the appointment of a receiver. The institution and
          maintenance of an action or judicial proceeding for, or pursuit of, provisional
          or ancillary remedies shall not constitute a waiver of the right of any
          party,
          even if it is the plaintiff, to submit the dispute to arbitration if such
          party
          would otherwise have such right. Each of the parties hereby submits
          unconditionally to the exclusive jurisdiction of the state and federal
          courts
          located in the County of Franklin, State of Ohio for purposes of this provision,
          waives objection to the venue of any proceeding in any such court or that
          any
          such court provides an inconvenient forum and consents to the service of
          process
          upon it in connection with any proceeding instituted under this Section
          13(j) in
          the same manner as provided for the giving of notice under this Agreement.
          Judgment upon the award rendered may be entered in any court having
          jurisdiction. The parties hereby expressly consent to the nonexclusive
          jurisdiction of the state and federal courts situated in the County of
          Franklin,
          State of Ohio for this purpose and waive objection to the venue of any
          proceeding in such court or that such court provides an inconvenient forum.
          The
          arbitrator shall have the power to award recovery of all costs (including
          attorneys’ fees, administrative fees, arbitrators' fees and court costs) to the
          prevailing party. The arbitrator shall not have power, by award or otherwise,
          to
          vary any of the provisions of this Agreement.


        (k)
          Delays
          or Omissions.
          No
          delay or omission to exercise any right, power, or remedy accruing to any
          party
          under this Agreement, upon any breach or default of any other party under
          this
          Agreement, shall impair any such right, power, or remedy of such nonbreaching
          or
          nondefaulting party, nor shall it be construed to be a waiver of or acquiescence
          to any such breach or default, or to any similar breach or default thereafter
          occurring, nor shall any waiver of any single breach or default be deemed
          a
          waiver of any other breach or default theretofore or thereafter occurring.
          All
          remedies, whether under this Agreement or by law or otherwise afforded
          to any
          party, shall be cumulative and not alternative.

         

        (l)
          No
          Strict Construction.
          The
          parties hereto have participated jointly in the negotiation and drafting
          of this
          Agreement. In the event an ambiguity or question of intent or interpretation
          arises under any provision of this Agreement, this Agreement shall be construed
          as if drafted jointly by the parties thereto, and no presumption or burden
          of
          proof shall arise favoring or disfavoring any party by virtue of the authorship
          of any of the provisions of this Agreement.

         

        
          
             

          

          
            15

            
              

            

          

          
             

          

        

         

        (m)
          No
          Subordination of Registration Rights.
          After
          the date of this Agreement, the Company will not grant to any Person any
          registration rights which would preclude the Investors from participating
          in any
          subsequent registration pursuant to any right granted in this
          Agreement.

         

        IN
          WITNESS WHEREOF, the parties have executed this Agreement as of the date
          first
          written above.

         


        [Signatures
          on following pages]

         

        
          
             

          

          
            16

            
              

            

          

          
             

          

        

         

        
          	 	 	 
	 	COMPANY:
	 	Neoprobe Corporation
	 
 	 
 	 
 
	
                	By:  	/s/
                  Brent L. Larson
	 	
                  

                  Brent
                    L. Larson, 

                  Vice
                    President -- Finance

                


        

        
           

           

          Signature
            page to Registration Rights Agreement

           

          
            
               

            

            
              17

              
                

              

            

            
               

            

             

          

        

        
          	 	 	 
	 	INVESTORS:
	 
 	 
 	 
 
	
                	/s/
                  David C. Bupp
	 	
                  
David
                  C. Bupp
	 	 
	 	 
	 	/s/ Cynthia B. Gochoco
	 	
                  
Cynthia
                  B. Gochoco
	 	 
	 	 
	 	/s/ Walter H. Bupp
	 	
                  

                  Walter
                    H. Bupp, 

                  by
                    David C. Bupp, his attorney in fact, under power of attorney
                    dated April
                    22, 2005

                


           

           

          Signature
            page to Registration Rights Agreement

           

          
            
               

            

            
              18