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