COLORIMETRIC METHOD FOR THE ESTIMATION OF GROWTH IN CUP ASSAYS

Abstract
A microbiological assay used for the determination of [alpha]-aceto-[alpha] hydroxybutyrate, an early intermediate in isoleucine biosynthesis, is described. The amount of growth in the agar surrounding Oxford cups was determined by measuring the amount of bacterial protein in the growth zone. This method permitted the estimation of the compound being tested without requiring sterilization of the solutions containing the compound.