ANTIBIOTIC ASSAY MEDIUM NO. 19 (as per USP)

The medium composition is in accordance to USP and CFR. This medium is used as seed agar for assay of antifungal agents like Amphotericin B and Nystatin. This medium is used for maintenance and inoculum development of Saccharomyces cerevisiae. This medium is also used for assaying mycostatic activity in pharmaceutical formulations. This medium is forumulated as reported by Kirshbam and Arret
Antibiotic assay medium No.19, is used as both base and seed medium for agar diffusion assay for antibiotics like Amphotericin B and Nystatin. Freshly prepared plates should be used for antibiotic assays. Test organisms are inoculated in sterile seed agar precooled to 40-45?C and spread evenly over the surface of solidified base agar. Pre-diffusion of antibiotics for 20 minutes in the agar by incubating at temperature below the optimal growth temperature for microorganism would facilitate better diffusion of antibiotic, followed by incubation of the plates for microbial growth.

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