Fibroblast variability in response to UV radiation and in a contraction assay. (A-C) p53 immunoblot of monolayer fibroblasts (500,000 per 35 mm plate) immediately after a timed exposure (0-120 min) to the same UV source for 3 strains (F15-17). Coomassie-stained PVDF or GAPDH blot shown as a loading control. Arrow in panel A indicates lane of the nonradiated cells. M = molecular weight marker; A = A-431 control lysate; H = HeLa control lysate.