Measurement of S period in growing cell populations by a graphic analysis of double labeling with 3H- and 14C-thymidine

A graphic analysis is presented for the measurement of S period in asynchronously growing cell populations by double labeling with 3H and 14C- thymidine. It is applicable to growth characteristics anywhere between an exponential and a near steady state. Measurements made on Ehrlich ascites tumors of two different ages agree well with the values obtained by the labeled mitoses technique.