OBSERVATIONS ON THE USE OF TETRAZOLIUM SALTS IN THE VITAL STAINING OF BACTERIA

Abstract

Studies on the vital staining of bacteria were carried out to determine the concentrations of tetrazolium salts required for optimal staining, and the amounts which could cause complete inhibition of bacterial growth. Four salts were studied: neotetrazolium chloride (NTC), triphenyltetrazolium chloride (TTC), blue tetrazolium (BT), and nitro-blue tetrazolium (NBT). Evidence has been presented to show that only living, actively metabolizing cells can reduce neotetrazolium to formazan.