Statistical methods for in vitro cell survival assays.

Statistical methods are presented for estimating and comparing survival curves obtained from experiments in which cells are exposed in vitro to increasing doses of a DNA-damaging agent. These methods, which are applicable in a variety of cell survival assays, are illustrated in the evaluation of two sets of experiments in which the colony-forming ability of fibroblast cell lines from 9 muscular dystrophy patients and 17 normal individuals were studied after exposure to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG).