Exhibit 99.15

To:           Brian McAlister
                Cornet Capital, Inc.

From:       Chuck Soponis
                OraGen, Inc.

Dear Brian:

In connection with our Agreement, I note one minor mistake made. Your compensation under the Agreement should be for 7,408 common shares of OraGen stock. This amount of stock will result in a post-split number of 800,064 shares of common stock following the Board's actions.

I trust this causes no problem for you. If you are in agreement with the changed numbers, please indicate your approval by signing this Memorandum for our files.

Agreed to and Approved:

Comet Capital, Inc.

By:   /s/ Brian McAlister
Brian McAlister