DNase Agar

DNase agar is prepared with DNA strands, Peptone, and Methyl Green dye. The Methyl Green will bind with the DNA strands and creates a blue-green color throughout the media. If the DNA is cleaved apart by enzymatic activity from the organism, this bond is lost as well as the coloration. DNase positive organisms will have patches of clearing around their colonies. This test is easiest to interperet by holding it against a light colored object with little to no variation in color across its surface.