Thiazolyl Blue Tetrazolium Bromide Synonym(s): 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, MTT, Methylthiazolyldiphenyl-tetrazolium bromide Empirical Formula (Hill Notation): C18H16BrN5S CAS No.: 298-93-1