NOVEL DISULFONATED TETRAZOLIUM SALT THAT CAN BE REDUCED TO A WATER-SOLUBLE FORMAZAN AND ITS APPLICATION TO THE ASSAY OF LACTATE-DEHYDROGENASE

A new tetrazolium salt, 2-(2,4-dinitriphenyl)-2H-5-tetrazolio]-1,3-ben zene disulfonate, sodium salt, that produces a highly water-soluble fo rmazan dye upon reduction by reduced nicotinamide adenine dinucleotide (NADH) was synthesized. The reduction of the compound by NADH at a ne utral pH is fast owing to its small reduction potential, The applicabi lity of the compound to the assay of lactate dehydrogenase is describe d in comparison with a prevalent tetrazolium salt.