Figure 1: γ-H2Ax labeling in kidney. Panel A shows γ-H2Ax immunolabeling in the Long-Evans rat kidney (positive control). A few podocytes (P) that line the urinary space (US) are labeled while other podocytes are not labeled. The tubular epithelia (TE) in panel A shows little or no staining. Panel B reveals that omitting the antibody from the immunolabeling procedure resulted in no staining within podocytes (negative control). The scale bar (20 μm) in panel B applies to panel A.