3H-thymidine incorporation method versus colony forming assay in the determination of anchorage-independent cell growth of rat sarcoma (XC) and Morris hepatoma 7777 (MH) cells.

The modification of 3H-thymidine incorporation method of Tanigawa was used to the estimation of anchorage-independent growth of virally and chemically transformed rat cells. The relationship between colony forming assay and 3H-TdR incorporation test was determined, depends on the composition of culture medium and the period of incubation of rat sarcoma (XC) cells with thymidine. The influence of exogenous mitogens (RFG, TGF beta 1 and insulin) and autocrine factor (at different step of purification) on the growth of Morris hepatoma 7777 (MH) cells was estimated by both methods. Regression analysis comparing the results of colony counting and thymidine incorporation revealed good correlation between the two methods. The modification can be used the determination of growth stimulating or growth inhibiting activity and in multistep purification procedure of autocrine growth factors.