Microscopic analyses of cell proliferation and apoptosis after different treatment combinations. (a & b) After different treatment combinations as described, cell growth of AW8507 & AW13516 cells were determined by counting cell numbers using Trypan blue dye exclusion assay. Cell numbers are given in percent of untreated controls. Data are means ± SD of three independent experiments. (c & d) Apoptosis was determined by DAPI staining, cells either untreated (Control) or treated with UC siRNA, Mcl-1L siRNA alone or in combination with IR. Apoptotic cells were counted in different fields and shown as percent of apoptosis relative to control. Data are means ± SD of three independent experiments. * indicates P < 0.05, ** P < 0.01.