An improved tissue culture assay. III. Alternate methods for measuring cell growth.

Simplified methods were described for the measurement of growth of human car cinoma cells in tissue culture: (a) determination of color intensity in lysates of cells stained with crystal violet (CV method), (6) determination of the reduction of 2,6dichlorophenol indophenol, and (c) determination of total organic solids (dichromate method). The three methods gave comparable measurements of relative cell growth and cor related well with the more laborious protein assay. The CV method was especially suitable for assaying large numbers of samples and was shown to measure the cytotoxicity in several compounds in a reproducible and precise manner. Standard errors per assay were comparable between protein and CV assays (approximately 20 per cent).