Microbioassay of nystatin with a yeast electrode

Abstract

Microbioassay of nystatin is achieved with an electrode composed of a yeast membrane and an oxygen electrode, based on the inhibitory action of the antibiotic on the respiration of the yeast. A linear relationship is obtained between the rate of current increase and the potency of nystatin. The minimum measurable nystatin concentration is 0.5 unit ml-1.The assay takes less than l h; the standard deviation is 1.2 unit ml -1 at the 27 USP unit ml -1 level.