AMENDMENT TO CREDIT AND SECURITY AGREEMENT

Exhibit 10.1

AMENDMENT TO CREDIT AND SECURITY AGREEMENT

THIS AMENDMENT (the “Amendment”), dated as of October 2, 2009, is entered into by and among MISONIX, INC., ACOUSTIC MARKETING RESEARCH, INC. d/b/a SONORA MEDICAL SYSTEMS, and HEARING INNOVATIONS INCORPORATED (collectively, the “Borrowers”), and WELLS FARGO BANK, NATIONAL ASSOCIATION (the “Lender”), acting through its Wells Fargo Business Credit operating division.

RECITALS

The Borrowers and the Lender are parties to a Credit and Security Agreement dated December 29, 2006 (as amended from time to time, the “Credit Agreement”). Capitalized terms used in this Amendment have the meanings given to them in the Credit Agreement unless otherwise specified.

The Borrowers have requested that certain amendments be made to the Credit Agreement, which the Lender is willing to make pursuant to the terms and conditions set forth herein.

NOW, THEREFORE, in consideration of the premises and of the mutual covenants and agreements herein contained, it is agreed as follows:

1. Section 1.1 of the Credit Agreement shall be amended by deleting the definition of “Minimum Loan Amount” in its entirety and replacing it with the following:

“‘Minimum Loan Amount’ shall mean $500,000.”

2.  Termination. The Borrowers acknowledge and agree that the term of the Credit Agreement shall not be renewed, and the Termination Date shall be December 29, 2009.

3.  No Other Changes. Except as explicitly amended by this Amendment, all of the terms and conditions of the Credit Agreement shall remain in full force and effect and shall apply to any advance or letter of credit thereunder.

4.  Asset Sale. The Borrowers have requested that the Lender agree to allow Acoustic to sell, assign, transfer and/or deliver to Medical Imaging Holdings, Inc. certain MRI products and other assets (the “Proposed Sale”), pursuant to the terms and conditions contained in the Asset Purchase Agreement, the September 16, 2009 draft of which (the “Draft APA”) is attached hereto. Wells Fargo consents to the Proposed Sale subject to Wells Fargo’s receipt of $1,804,665.25 from the proceeds of the Proposed Sale, such that all Advances made by Wells Fargo based upon the Purchased Assets will have been paid in full by the Borrowers and that there would remain excess Availability of at least $500,000 after giving effect to the Proposed Sale.

5.  Conditions Precedent. This Amendment shall he effective when the Lender shall have received an executed original hereof, together with each of the following, each in substance and form acceptable to the Lender in its sole discretion:

(a) Execution and delivery to the Lender of a fully executed copy of this Amendment.

(b) Execution and delivery to the Lender of a fully executed Securities Account Control Agreement (the “Control Agreement”) in form and substance acceptable to the Lender in its sole discretion.

(c) Funding of an additional $1,000,000 (the “Additional Cash Collateral”) to account # [omitted] at Wells Fargo Brokerage Services, LLC, which account and Additional Cash Collateral shall he subject to the Control Agreement.

(d) Such other matters as the Lender may require.

6.  Representations and Warr