Clonogenic survival analysis after Mcl-1L knockdown and/or irradiation. (a & b) AW8507 & AW13516 cells were either untreated, or treated with siRNA. After 24 hrs, cell culture dishes were treated with increasing doses of ionizing irradiation (0, 2, 4, 6 8 and 10 Gy) as indicated. Survival was assessed by performing clonogenic assay as described in Methods. Data are given as percentage survival of untreated cells and represent the means (±SD) of three independent colony formation experiments.