Fig. (1) Effect of NiCl2 on U2OS (A) and HaCat (B) viability. The cells were exposed to increasing NiCl2 concentrations for 24, 48 and 72h and cell viability was detected and quantified by flow cytometry as described in the Materials and Methods (n = 5). *(p<0.05) indicates significant differences between cell culture treated with NiCl2 and untreated controls.