Baird Parker Agar is used with Egg Yolk Tellurite Enrichment for the detection, isolation and enumeration of coagulase-positive staphylococci in foods and cosmetics. Potassium Tellurite and Lithium Chloride selectively suppress the growth of most bacteria but allow the growth of Staphylococci which is also enhanced by the addition of sodium pyruvate and glycine. The differentiation of coagulase-positive staphylococci is noted by the reduction of Potassium Tellurite which results in a black colony. Staphylococci that contain lecithinase break down the egg yolk and cause a clear zone. Opaque zones may form as a result of lipase activity.