Exhibit 5.1 SCHWARTZ, WARREN & RAMIREZ A LIMITED LIABILITY COMPANY O ATTORNEYS AT LAW 41 SOUTH HIGH STREET o COLUMBUS, OHIO 43215-6188 (614) 222-3000 o FAX (614) 224-0360 ROBERT S. SCHWARTZ DAYTON, OHIO (513) 228-0144 (614) 222-3050 http://www.swrlaw.com rschwart@swrlaw.mhs.compuserve.com May 8, 1996 Neoprobe Corporation 425 Metro Place North Dublin, Ohio 43017 Re: Offering of Common Stock Gentlemen: You have requested our opinion in connection with the offering (the "Offering") of Class K and Class L Warrants and 150,000 shares of Common Stock, par value $.001 per share (the "Common Stock"), of Neoprobe Corporation, a Delaware corporation (the "Company") issuable upon exercise of Class K and Class L Warrants (the "Warrants"), which securities are registered on Post-Effective Amendment No. 2 to Registration Statement on Form S-3 (No. 33-86000), filed with the Securities and Exchange Commission pursuant to the Securities Act of 1933 (the "Registration Statement"). Although we have acted as counsel to the Company in connection with the Offering and various other matters in the past, our advice to and representation of the Company have been limited to the specific matters referred to us from time to time by the Company; accordingly, we may be unaware of certain matters of a legal nature concerning the Company. We have examined and relied upon the following documents and instruments for the purpose of giving this opinion which, to our knowledge and in our judgment, are all of the documents and instruments that are necessary for us to examine for such purpose: i. The Registration Statement, the prospectus filed therewith (the "Prospectus") and all amendments and exhibits thereto; ii. The forms of Warrants; iii. The corporate minute books of the Company, including copies of the Company's Restated Certificate of Incorporation, as amended, and Amended and Restated Bylaws; iv. An officer's certificate executed by an officer of the Company certifying certain factual information; and v. A secretary's certificate executed by the secretary of the Company certifying certain corporate information. In giving our opinion, we have assumed, without investigation, the authenticity of any document or instrument submitted to us as an original, the conformity to the authentic original of any document or instrument submitted to us as a certified, conformed or photostatic copy, the genuineness of all signatures on such originals or copies and the authority and capacity of each signatory. Neoprobe Corporation May 8, 1996 Page 2 Based upon the foregoing, we are of the opinion that the Warrants constitute valid and legally binding obligations of the Company enforceable against the Company in accordance with their respective terms. The shares of Common Stock issuable upon the exercise of the Warrants have been duly authorized and reserved for issuance upon the exercise of the Warrants and, upon issuance, delivery and payment therefor pursuant to the terms of the Warrants, will be validly issued, fully paid and nonassessable. The opinion set forth above is subject to the following qualifications: A. The legality, validity and enforceability of the Warrants are subject to the effect of any applicable bankruptcy, insolvency or similar law affecting creditors' rights in general. B. The legality, validity and enforceability of the Warrants are subject to general principles of equity, whether considered in actions at law or suits in equity, including, without limitation, good faith, unconscionability, reasonableness and the possible unavailability of specific performance and injunctive relief. C. No opinion is expressed herein as to the application of any state securities or blue sky laws to the offer, sale and issuance of the Warrants or the shares of Common Stock issuable upon the exercise thereof. D. Members of our firm are qualified to practice law in the State of Ohio and nothing contained herein shall be deemed to be an opinion as to any other law other than the General Corporation Law of the State of Delaware and the federal law of the United States. E. The opinions set forth herein are expressed as of the date hereof and we do not have any obligation to advise you of any changes, after the date hereof, in the facts or the law upon which these opinions are based. F. This opinion is furnished by us solely for your benefit and is intended to be used as an exhibit to the Registration Statement and filings with various state securities authorities in connection with the Offering, and such entities may rely on this opinion as if it were addressed to and had been delivered to them on the date hereof. Except for such use, neither this opinion nor copies hereof may be relied upon by, delivered to any person or entity, or quoted in whole or in part without our prior written consent. G. We consent to the reference to our firm name under the caption LEGAL MATTERS in the Prospectus and to the use of our opinion as an exhibit to the Registration Statement. In giving these consents, we do not admit that we come within the category of persons whose consent is required under Section 7 of the Securities Act of 1933, or the rules and regulations of the Securities and Exchange Commission thereunder. Very truly yours, SCHWARTZ, WARREN & RAMIREZ A LIMITED LIABILITY COMPANY By: /s/Robert S. Schwartz ---------------------------------------- Robert S. Schwartz, a member of the firm