Baird Parker Agar- Composition, Principle, Preparation, Results, Uses


Baird Parker Agar is a selective and differential medium for the isolation and enumeration of coagulase-positive staphylococci from food and clinical samples. It contains the following ingredients and their quantities per liter of distilled water:

  • Tryptone: 10 g
  • HM peptone B: 10 g
  • Yeast extract: 5 g
  • Sodium pyruvate: 10 g
  • Lithium chloride: 5 g
  • Glycine: 12 g
  • Agar: 20 g

The medium is supplemented with egg yolk emulsion and potassium tellurite solution after autoclaving. The egg yolk emulsion provides enrichment and also serves as an indicator of lecithinase and lipase activity. The potassium tellurite solution inhibits most of the contaminating microflora except Staphylococcus aureus and also imparts a black color to the colonies that can reduce tellurite. The final pH of the medium is 7.0 ± 0.2 at 25°C.