Figure 1: Induction of p53 by nutlin and UVB irradiation in murine epidermis. Mice (n=15) were treated on the counterlateral halves of dorsal skin with nutlin (C, D) or the isopropanol vehicle (A, B). They were un-irradiated (A, C) or irradiated with 100 mJ/cm2 UVB (B, D), as described in Methods. Skin samples were taken 8 h after irradiation and stained with anti-p53 antibody with peroxidase visualisation (brown color). Arrows show p53-positive nuclei in mice treated with UVB and nutlin. Magnification x400.