Fig. 1.

A survival curve for the Hela, HepG2 and MEC-1 cell lines, as determined by clonogenic assay. Exponentially growing cells were plated and irradiated, the cells were taken at the indicated time intervals after irradiation of ¹²C⁶⁺ and a clonogenic assay was performed. The means and SD are shown for three independent experiments with 3 replicates in each experiment. Untreated cells served as a control. After incubation for two weeks, colonies with cells greater than 50 were counted. a Hela cells; b HepG2 cells; c MEC-1 cells. *P < 0.05, **P < 0.01, ***P < 0.001 vs. 0 Gy irradiation