Abstract
There is considerable variation between the sulfhydryl induced in vitro reduction of the oxidation-reduction indicators (2,3,5-triphenyltetrazolium chloride, 2,3-diphenyl 5-methyl tetrazolium chloride, neotelra-zolium chloride, neotetrazolium phosphate - 2B, blue tetrazolium , tetrazolium violet, potassium tellurite, methylene blue, and resazurin). The neotetrazolium salts and potassium tellurite show the greatest reducing activity. The reduction of the indicators by oxidized sulfhydryl compounds in the presence of potassium cyanide closely parallels the reduction of the same indicators by reduced sulfhydryl compounds. Iodoacetamide is the most effective sulfhydryl inhibitor as demonstrated by indicator reduction.