How do you make a DNase Agar?

Preparation of DNAse agar:

  1. The medium is used at a concentration of 3.9 grams in every 100 ml of distilled water.
  2. Prepare and sterilize as instructed by the manufacturer.
  3. When the medium has cooled to 50-55°C, mix well and dispense in sterile petri dishes.
  4. Date the medium and give it a batch number.

What grows on DNase Agar?

Overview. Deoxyribonuclease (DNase) test is used to determine an organism’s ability to hydrolyze DNA and use it as a source of carbon and energy for growth. Used mainly to differentiate Staphylococcus aureus from other Staphylococci.

What is DNase test in microbiology?

The deoxyribonuclease (DNase) test detects the degradation of DNA by bacterial species that produce DNase. The DNase test may be performed on plate media and is available in some commercial tests, e.g., QuadFERM+.

What is the appearance of a positive DNase test agar?

The action of DNase depolymerizes the DNA structure releasing methyl green; when not combined at this pH methyl green becomes colorless resulting in colorless halos around DNase-positive colonies. 1. Allow medium to reach room temperature prior to inoculation.

Which bacteria is producing DNase?

Various hemolytic streptococci, hemolytic staphylococci, and micrococci were tested for production of deoxyribonuclease (DNase). In general, beta-hemolytic pathogenic streptococci of human origin produced highest concentrations of DNase.

Why is methyl green added to DNase?

DNase Test Agar w/Methyl Green is a solid medium used to detect the deoxyribonuclease (DNase) activity in microorganisms. For the methyl green modification, the dye methyl green is able to bind to polymerized DNA to form a stable green complex at pH 7.3.

What is a positive DNase test?

Does Staphylococcus aureus grow on DNase agar?

BD DNase Test Agar is a standard medium for the determination of deoxyribonuclease. 5,6 It is used mainly in the identification of Staphylococcus aureus and its differentiation from S. epidermidis or other DNase negative staphylococci, and for the differentiation of Serratia from Klebsiella/Enterobacter.