ANTIBIOTIC ASSAY MEDIUM NO. 19 (VEG.)

Antibiotic Veg Assay Medium No.19 is prepared by incorporating vegetable peptones in place of animal peptones, making the medium BSE, TSE risks free. This can be used for the same purpose of Antibiotic Assay Medium No.19 for the assay of various antibiotics. Grove and Randall have elaborately elucidated the methods to perform these assays and various media used for the same. Schmidt and Moyer have reported the use of antibiotic assay medium for the liquid formulation used in the performance of antibiotic assay. These media are also recommended by USP and FDA. This medium is as per specification of Krishbaum and Arett, used as seed agar for assay of antifungal agents like Amphotericin B, Nystatin, Netamycin and Candidicin etc. For similar applications, Antibiotic Veg Assay Medium No.19 can be used. The indicator organism used is Saccharomyces cerevisiae. This medium can also be used for maintenance and inoculum development of Saccharomyces cerevisiae as well as for assaying mycostatic activity in pharmaceutical formulations.
Freshly prepared plates should be used for antibiotic assays. Pre-diffusion of antibiotics for 20 minutes in the agar by incubating at temperature below the optimal growth temperature for microorganisms facilitates better diffusion of antibiotics followed by incubation of the plates at optimal temperature for microbial growth. Test organisms are inoculated in sterile seed agar precooled to 40-45?C and spread evenly over the surface of solidified base agar

for microbiological assay of Amphotericin B, Netamycin & Nystatin using Saccharomyces cerevisiae