Baird-Parker Agar
Encyclopedia
Baird–Parker agar is a type of agar
used for the selective isolation of gram-positive
Staphylococci species. It contains lithium chloride
and tellurite
to inhibit the growth of alternative microbial flora, while the included pyruvate and glycine
promote the growth of Staphylococci. Staphylococcus colonies show up black in colour with clear zones produced around them.
Agar
Agar or agar-agar is a gelatinous substance derived from a polysaccharide that accumulates in the cell walls of agarophyte red algae. Throughout history into modern times, agar has been chiefly used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture medium...
used for the selective isolation of gram-positive
Gram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
Staphylococci species. It contains lithium chloride
Lithium chloride
Lithium chloride is a chemical compound with the formula LiCl. The salt is a typical ionic compound, although the small size of the Li+ ion gives rise to properties not seen for other alkali metal chlorides, such as extraordinary solubility in polar solvents and its hygroscopic...
and tellurite
Tellurite
Tellurite is a rare oxide mineral composed of tellurium dioxide .It occurs as prismatic to acicular transparent yellow to white orthorhombic crystals. It occurs in the oxidation zone of mineral deposits in association with native tellurium, emmonsite and other tellurium minerals. Its name comes...
to inhibit the growth of alternative microbial flora, while the included pyruvate and glycine
Glycine
Glycine is an organic compound with the formula NH2CH2COOH. Having a hydrogen substituent as its 'side chain', glycine is the smallest of the 20 amino acids commonly found in proteins. Its codons are GGU, GGC, GGA, GGG cf. the genetic code.Glycine is a colourless, sweet-tasting crystalline solid...
promote the growth of Staphylococci. Staphylococcus colonies show up black in colour with clear zones produced around them.