At 24 h of cisplatin exposure, RPTC monolayers were fixed in 3.7% formaldehyde, incubated in the presence of 8 μm DAPI for 2 h at room temperature, and evaluated under Zeiss fluorescent microscope (Axioskop). Pictures were taken using Hamamatsu color chilled 3CCD digital camera. A, control; B, 50 μm cisplatin; C, 50 μm PD98059; D, 50 μm PD98059 + 50 μm cisplatin; E, 10 nM Go6976; F, 10 nm Go6976 + 50 μm cisplatin. Presented data are representative of three independent experiments (cell isolations). Original magnification, ×400.