A new,rapid colorimetric assay for quantitative determination of cellular proliferation,growth inhibition,and viability

Summary A sensitive spectrophotometric test has been developed to rapidly quantitate cell growth and viability on monolayer cultures. The method consists of staining fixed cells with the supravital dye Janus green, extraction of the dye from these cells with absolute alcohol, spectrophotometric measurement of the eluant, and referring optical density (OD) readings to a previously established standard curve such that measurements can be expressed directly as number of surviving cells. Staining of cells with the same colorant before fixation allows microscopical or colorimetric quantitation or both of damaged cells still adherent to the substratum. Both steps can be conveniently carried out on the same cell culture plate. More rapid and easier to perform than the usual cell counting or tritiated thymidine assays, this technique may prove to be useful in evaluation of the effect of growth promoting substances, growth inhibitors, or cytotoxic agents on monolayer cultures.