CAS 150849-53-9: 1,3-Benzenedisulfonic acid, 4-[[2-(4-iodophenyl)diazenyl][2-(4-nitrophenyl)hydrazinylidene]methyl]-, sodium salt (1:1)

4-[1-(4-Iodophenyl)-5-(4-nitrophenyl)-formaz-3-yl]-1,3-benzene disulfonate, disodium salt (WST) is a cell proliferation assay that uses formazan to measure the activity of cytosolic enzyme NADH:oxidoreductase (NADH:oxygen oxidoreductase). WST is used to assess the cytotoxicity of compounds in vitro and can be used to validate the cytotoxicity of compounds. The assay quantifies cellular metabolism by measuring the conversion of NADH into formazan. The monosodium salt, formazan product is measured by measuring absorbance at 450 nm. The disodium salt, formazan product is measured by using a uv detector set at 254 nm. Acetonitrile and chromatography are used for purification and validation steps.