DNase agar is used primarily in clinical laboratories to differentiate Staphylococcus aureus from other Staphylococci based on deoxyribonuclease activity. Following incubation of the plate and confirmation of a pure growth of Staphylococci, the surface of the medium is covered with a small quantity of 1M hydrochloric acid to precipitate the DNA. Staphylococcus aureus produce DNase enzymes that hydrolyse DNA resulting in a clear area around the colonies, described as being DNase positive, whereas coagulase negative Staphylococci do not produce clearing.
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.
- Storage temperature: 2 to 8°C
- Appearance: firm gel
- Colour: straw
- Recommended incubation: aerobically at 37°C for 16 to 24 hours
- pH: 7.3 ± 0.2
- Plate size: 90mm
This product has met the following criteria to qualify for the following awards: