Exhibit 5.1

                        [Pepper Hamilton LLP Letterhead]


                                          November 16, 2001


OraSure Technologies, Inc.
150 Webster Street
Bethlehem, Pennsylvania 18015

            Re:   Registration Statement on Form S-3

Ladies and Gentlemen:

            We have acted as counsel to OraSure  Technologies,  Inc., a Delaware
corporation  (the  "Company"),  in connection  with the  registration  under the
Securities  Act of 1933,  as amended (the  "Act"),  of an aggregate of 4,094,882
shares of the Company's common stock,  $0.000001 par value (the "Shares"),  held
by HealthCare Venture Partners V, L.P. and Pennsylvania Early Stage Partners GP,
LLC.

            This opinion is delivered in  accordance  with the  requirements  of
Item 601(b)(5) of Regulation S-K under the Act.

            We  have  examined  originals  or  copies,  certified  or  otherwise
identified to our  satisfaction,  of (i) the Registration  Statement on Form S-3
covering  the  Shares  (the  "Registration   Statement");   (ii)  the  Company's
Certificate of Incorporation and Bylaws, as in effect on the date hereof;  (iii)
certain  resolutions of the Board of Directors of the Company relating to, among
other things, the issuance of the Shares; and (iv) such other documents relating
to the  Company  and the  proposed  issuance  of the  Shares  as we have  deemed
necessary or appropriate as a basis for the opinions set forth below.

            In our  examination,  we have  assumed  the  legal  capacity  of all
natural  persons,  the  genuineness of all signatures,  the  authenticity of all
documents   submitted  to  us  as  certified  or  photostatic   copies  and  the
authenticity of the originals of such latter documents. As to any facts material
to the opinions  expressed  herein which were not  independently  established or
verified,  we have relied upon  statements and  representations  of officers and
other representatives of the Company and others.

            Members of our firm are admitted to the Bar of the  Commonwealth  of
Pennsylvania, and we express no opinion as to the laws of any other jurisdiction
other than the  Federal  laws of the United  States of America  and the  General
Corporation Law of the State of Delaware ("GCL").

            Based upon and subject to the foregoing,  we are of the opinion that
the  Shares  have  been  duly  and  validly   issued  and  are   fully-paid  and
non-assessable by the Company under the GCL.

            We hereby consent to the filing of this opinion as an exhibit to the
Registration  Statement  and to the  reference  to this firm  under the  caption
"Legal Matters" in the prospectus filed as part of the  Registration  Statement.
In giving this  consent,  we do not hereby  admit that we are in the category of
persons whose consent is required under Section 7 of the Act.

            This opinion is furnished by us, as your counsel, in connection with
the  filing  of the  Registration  Statement  and,  except  as  provided  in the
immediately  preceding  paragraph,  is not to be  used,  circulated,  quoted  or
otherwise  referred  to for  any  other  purpose  without  our  express  written
permission or relied upon by any other person.

                                          Very truly yours,

                                          /s/ PEPPER HAMILTON LLP