Figure 1: Cr(VI)-induced apoptosis in human dermal fibroblasts. Human dermal fibroblasts were treated with 5µM Cr(VI) for 16 and 24-hours and the cells were stained with TUNEL reagent and DAPI to detect apoptotic and total nuclei, respectively. Cells treated with DNase were used as positive control for apoptosis. The experiment was repeated four times, and the results of a representative 24-hour experiment are presented. TUNEL positive apoptotic nuclei are presented in the upper row, and the same cells stained with DAPI showing apoptotic and non-apoptotic nuclei are presented in the lower row.