DNase Agar is used primarily in clinical laboratories to differentiate Staphylococcus aureus from other staphylococci based on deoxyribonuclease activity. Staphylococcus aureus produce DNase enzymes that hydrolyse DNA resulting in a colourless zone around the colonies, described as being DNase positive, whereas coagulase negative staphylococci do not produce clearing. This particular formulation can also be used for Streptococci and Serratia.
NB: As with most tests of this type a positive result should not be taken in isolation and other appropriate tests, e.g. Coagulase Test, Latex Agglutination etc, should be carried out.