YEAST BEEF AGAR (ANTIBIOTIC ASSAY MEDIUM NO. 4)

Yeast Beef Agar (antibiotic assay medium no. 4) is suitable for plate counts in pharmaceutical and related products and for the microbial assay and detection of antibiotics like penicillin in milk. These medium is formulated in accordance to the specifications and procedures listed by the Food and Drug Administration. This medium is identical numerically with name assigned by Grove and Randall.
The cylinder plate method is recommended as the standard for quantification of ?-lactam residues. A description of the cylinder plate method for detecting penicillin in dry powdered milk is given by Kramer et al. The same basic procedure is also recommended in the assay of penicillin in fluid milk.

for detection of Penicillin-G in milk samples