C: Ubc9 D100A impairs cell survival upon H2O2 treatment. Ubc9 wt or Ubc9 D100A cells were transfected with siRNA against endogenous Ubc9 for 72h, transferred into 6 well plates (20 000 cells / well) and treated with increasing H2O2 concentration for 1h. Ten days later, cells were washed with PBS, fixed with 4% formaldehyde and stained with crystal violet. The area occupied by the cells was evaluated using ImageJ and the ColonyArea plugin. An arbitrary value of 1 was given to the area occupied by non-treated cells. The graph is showing the mean of 4 independent experiments. Error bars are S.E.M. *: p < 0.05 