A COMBINES ASSAY OF CELL VIABILITY AND IN-VITRO CYTOTOXICITY WITH A HIGHLY WATER-SOLUBLE TETRAZOLIUM SALT, NEUTRAL RED AND CRYSTAL VIOLET

Cell viability and in vitro cytotoxicity assay methods were developed using a combination of dyes, yl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1, 3-benzene disulfonate (WST-1), neutral red (NR) and crystal violet (CV ), with HeLa cells as a bioindicator. As WST-1 produces a highly water soluble and non-cytotoxic formazan dye, it allows each assay to be ca rried out in one culture dish. The combined cell viability assay using WST-1, NR and CV gave an absorbance that correlated linearly with the number of cells over the range 1000 to 50000 cells/well. The combined assay was applied to the evaluation of the IC50 values for sodium dod ecyl sulfate as a model toxicant, which yielded similar values to thos e obtained with each assay independently.