Exhibit 5.1

                              SNELL & WILMER L.L.P.

                           3800 HOWARD HUGHES PARKWAY

                                   SUITE 1000

                              LAS VAGAS, UTAH 89109



                                November 13, 2006


Applied DNA Sciences, Inc.
25 Health Sciences Drive, Suite 113
Stony Brook, New York 11790

Ladies and Gentlemen:

         We have acted as local counsel to Applied DNA Sciences, Inc., a
placeStateNevada corporation (the "Company"), in connection with the preparation
and filing by the Company with the Securities and Exchange Commission (the
"Commission") of a Registration Statement on Form SB-2 (as amended, the
"Registration Statement") under the Securities Act of 1933, as amended (the
"Act"). The Registration Statement relates to the sale, from time to time, by
certain stockholders of the Company (the "Selling Stockholders") identified in
the prospectus included in the Registration Statement (the "Prospectus") of up
to an aggregate of 41,417,467 shares of the Company's common stock (the
"Shares"). 21,727,967 of the Shares are currently outstanding (the "Outstanding
Shares") and the remaining 19,689,500 Shares (the "Warrant Shares") are issuable
upon the exercise of issued and outstanding common stock purchase warrants (the
"Warrants"), as more specifically described in the Prospectus.

         We have examined and relied upon executed originals, counterparts, or
copies of such documents, records, and certificates (including certificates of
public officials and officers of the Company) as we considered necessary or
appropriate for enabling us to express the opinions set forth herein. In all
such examinations, we have assumed the authenticity and completeness of all
documents submitted to us as originals and the conformity to originals and
completeness of all documents submitted to us as photostatic, conformed,
notarized or certified copies.

         Based on the foregoing, and subject to the qualifications stated
herein, we are of the opinion that:

         1. The Outstanding Shares are validly issued, fully paid, and
nonassessable.

         2. The Warrant Shares issuable on exercise of the Warrants are duly
authorized and reserved for issuance and, when issued and delivered in
accordance with the terms of the Warrants, including but not limited to payment
in full of the exercise price for the Warrant Shares, the Warrant Shares will be
validly issued, fully paid, and nonassessable.



         We express no opinion concerning the laws of any jurisdiction other
than the laws of the United States of America and the State of
Nevada.

         We hereby consent to the filing of this letter as an exhibit to the
Registration Statement and to the reference to this firm under the caption
"Legal Matters" in the Prospectus. 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 or the rules and regulations of the Commission thereunder.

         The foregoing opinions are rendered as of the date hereof, and we
assume no obligation to update such opinions to reflect any facts or
circumstances which may hereafter come to our attention or any changes in the
law which may hereafter occur.

                                                     Sincerely,

                                                     /s/ Snell & Wilmer L.L.P.

                                                     Snell & Wilmer L.L.P.