A water-soluble tetrazolium salt useful for colorimetric cell viability assay

The application of a tetrazolium salt, 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium, monosodium salt (WST-8), to cell viability assays and in vitro drug sensitivity tests is described. With a higher sensitivity as a chromogenic indicator for cell viability compared with conventional tetrazolium salts, WST-8 produced results of cell viability and IC50 values that were in good agreement, respectively, with the MTT method and [3H]thymidine uptake method.