Figure 3. Clonogenic survival of IR exposed cells after H2A.Z depletion. U2OS cells transfected with the different siRNA were (A) plated to evaluate clonogenic efficiency or (C) exposed to ionizing radiations 24 h later and clonogenic assay performed. The same protocol was applied with the RG37 cells (B) to evaluate clonogenic efficiency and (D) to examine cell survival after ionizing radiations exposure. Colonies were revealed 10 d later by staining the plates with crystal violet. Results are the mean+/− sd of triplicate.