Correction factors for the diphenylamine test for deoxyribonucleic acid in yeasts.

The diphenylamine assay for DNA content of yeast is unsatisfactory due to the presence of a yeast component which inhibits the colour reaction. The inhibitor is found in a wide range of yeast species and has not been identified. The relationships between the degree of inhibition and cell concentration, temperature and time of hydrolysis and extraction have been described. A formula for correction of the inhibition has been derived.