KM0066 – DNASE Agar with Methyl Green

//KM0066 – DNASE Agar with Methyl Green

KM0066 – DNASE Agar with Methyl Green

DNase agar is used primarily in clinical laboratories to differentiate pathogenic Staphylococcus aureus from other staphylococci based on deoxyribonuclease (DNase) activity.
The tryptone provides the required carbon, nitrogen and vitamins. Sodium chloride maintains the osmotic balance. The addition of DNA to the base medium provides a simple method to check for DNase activity. The methyl green fades into a colourless compound if the DNA in the medium is depolymerised.
Organisms that can produce sufficient quantity of a DNase enzyme will hydrolyse the DNA resulting in a clear area around the colonies. Whereas DNase negative organisms will 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.

 

SKU: KM0066 Category:

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Staphylococcus aureus NCTC 12981 Growth, white colonies and clear zones surrounding colonies
Staphylococcus epidermidis NCTC 13360 Growth, white colonies and no clear zones surrounding colonies

 

Formula*

g/L
Tryptone 20.0
Deoxyribonucleic acid 2.0
Sodium chloride 5.0
Agar 14.8
Methyl green 0.05
Total 41.85
*Adjusted/supplemented as required to meet performance requirements

Preparation

Suspend 41.85g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Sterilise at 121°C for 15 minutes with frequent stirring to completely dissolve the medium. Cool to 45-50°C and aseptically dispense into appropriate sterile containers.