Exhibit 5.1

The New York Times Building

37th Floor

620 Eighth Avenue

New York, NY 10018-1405

212.808.2700

Fax 212.286.9806

November 23, 2015

Applied DNA Sciences, Inc.
50 Health Sciences Drive

Stony Brook, NY 11790

Re:    Registration Statement on Form S-3 (Registration No. 333-202432)

Ladies and Gentlemen:

Reference is made to the Registration Statement on Form S-3 (Registration No. 333-202432), as amended (the “Initial Registration Statement”), filed by Applied DNA Sciences, Inc., a Delaware corporation (the “Company”) with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”), and declared effective by the Commission on March 10, 2015, and the Company’s additional Registration Statement on Form S-3 filed by the Company with the Commission on November 23, 2015 pursuant to Rule 462(b) under the Act and deemed effective upon filing (the “462(b) Registration Statement,” and together with the Initial Registration Statement, the “Registration Statements”). We are rendering this supplemental opinion in connection with the prospectus supplement, dated November 23, 2015, together with the Company’s prospectus dated March 10, 2015, as filed by the Company with the Commission pursuant to Rule 424(b)(5) under the Act (the “Prospectus”), relating to the offering by the Company of 2,500,000 shares of the Company’s common stock, par value $0.001 per share (the “Shares”). We understand that the Shares are to be offered and sold in the manner set forth in the respective Securities Purchase Agreements entered into by the Company with the purchasers named in the signature pages thereto (collectively, the “Securities Purchase Agreements”).

We have made such examination of law, and examined the originals, or copies certified or otherwise identified to our satisfaction, of such records, documents, certificates and other instruments, as we have deemed appropriate to give the opinions set forth below. In rendering this opinion, we have assumed the genuineness and authenticity of all signatures on original documents, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as certified or photostatic copies, the accuracy and completeness of all documents and records reviewed by us, the accuracy, completeness and authenticity of certificates issued by any government official, office or agency and the absence of change in the information contained therein from the effective date of any such certificate. As to any facts material to the opinion expressed herein which were not independently established or

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Applied DNA Sciences, Inc.

November 23, 2015

Page 2

verified, we have relied upon statements and representations of officers and other representatives of the Company and others.

We express no opinion herein as to the law of any state or jurisdiction other than the General Corporation Law of the State of Delaware, including the statutory provisions and all applicable provisions of the Constitution of the State of Delaware and reported judicial decisions interpreting the foregoing. Without limiting the generality of the foregoing qualification, we express no opinion as to compliance with any federal or state securities or “blue sky” laws, including without limitation the securities laws of the State of Delaware.

Based upon and subject to the assumptions and qualifications set forth herein, we are of the opinion that the Shares have been duly authorized and, when issued and delivered in accordance with the terms of the Securities Purchase Agreements and upon receipt by the Company of the consideration therefor provided therein, will be validly issued, fully paid and non-assessable.

This opinion is being furnished to you in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statements or any Prospectus Supplement related to the Registration Statements, other than as expressly stated herein with respect to the Shares. We assume no obligation to supplement this opinion if any applicable law changes after the date hereof or if we become aware of any fact that might change the opinion expressed herein after the date hereof. No opinion is rendered as to matters not specifically referred to herein and under no circumstances may any person infer from anything stated or not stated herein any opinion with respect to which such specific reference is not made.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statements. In giving this consent, we do not admit that we are within the category of persons whose consent is required by Section 7 of the Securities Act or the rules or regulations of the Commission thereunder.