ANTIBIOTIC ASSAY MEDIUM NO. 13 (NYSTATIN ASSAY BROTH) (VEG.)

Description

Antibiotic Veg Assay Medium No. 13 is prepared by incorporating vegetable based 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. 13 is formulated in accordance to CFR and is numerically identical with the name assigned by Groove and Randall. Groove and Randall had elucidated the methods to perfrom antibiotic assays. Schmidt & Moyer reported the use of antibiotic assay medium for liquid formulation in performance of antibiotic assay. This medium is widely used in turbidometric assay of antifungals like Candicidin using test organisms like Saccharomyces cerevisiae. This is medium is also termed Sabouraud Liquid Broth Modified or Fluid Sabouraud Medium. This medium facilitates enhanced growth of test organism Saccharomyces cerevisiae employed in assay of Candicidin, a polyene antibiotic with antifungal activity. Assay is performed by enumerating the blastospores or by analysing the turbidity of the medium. Optimal pH for growth of Saccharomyces cerevisiae is maintained in this medium. Turbidimetric antibiotic assay is based on the change or inhibition of growth of a test microorganism in a liquid medium containing a uniform concentration of an antibiotic. After incubation of the test organism in the working dilutions of the antibiotics, the amount of growth is determined by measuring the light transmittance using spectrophotometer. The concentration of antibiotic is determined by comparing amounts of growth obtained with that given by the reference standard solutions. Use of this method is appropriate only when test samples are clear.