The application of cryobiology to the microbiological assay of nystatin
Cosgrove, R.F.; Beezer, A.E.; Miles, R.J.
Journal of Pharmacy and Pharmacology 31(2): 83-86
1979
ISSN/ISBN: 0022-3573 PMID: 33257 Document Number: 143297
Improvements in the reproducibility of nystatin agar diffusion assays were achieved by the use of liquid N2 stored inocula [Saccharomyces cerevisiae] and deep frozen standard stock solutions. The overall percentage variability of the assay was reduced from over 5% with daily prepared standards and inocula to around 1% with a frozen inocula and to 0.6% with a combination of frozen inocula and standards. The implications of these improvements in the standardization of nystatin assays and microbiological assays generally are discussed.