Assays and statistical analyses for antibiotic standards

Some microbiological assays and statistical analyses of test results used by the National Center for Antibiotics Analysis are described for the establishment of offical antibiotic reference standards. Examples are given of both cylinder plate agar diffusion assays and turbidimetric assays. Formulas providing simple and quick analyses of data are shown for calculating potency, determining limits for the potency, and performing validity tests on the results.