for microbiological assay of antibiotics. ANTIBIOTIC ASSAY MEDIUM No. 2 (BASE AGAR) (VEG.) is used for testing the potency of antibiotics by the inhibitory effects on microorganisms. The cylinder assay plate is based on the diffusions of the antibiotics under test, measuring the size of the zones of inhibition of the microorganisms. This media is formulated as according to the guidelines of the USP. Medium contains Pancreatic digest of animal tissue, Beef extract and Yeast extract those provides nitrogen, carbon and vitamins (particularly B group) sources to the medium. Dextrose is added as a source of carbohydrate. Agar is a solidifying agent.