Plate Count Agar and Standard Methods Agar (Plate Count Agar; Tryptone Glucose Yeast Agar) are used for obtaining microbial plate counts from milk and dairy products, foods, water and other materials of sanitary importance.
SUMMARY AND EXPLANATION
Plate Count Agar and Standard Methods Agar are made according to the American Public Health Association (APHA) formulation. They are recommended for obtaining plate counts for milk and other dairy products and may also be used to determine the sanitary quality of foods, water and other materials.
Enzymatic digest of casein provides the amino acids and other complex nitrogenous substances necessary to support bacterial growth. Yeast extract primarily supplies the B-complex vitamins, and dextrose is an energy source. TTC is reduced to the insoluble formazan inside the bacterial cell producing red-colored colonies.