DNA was isolated from the renal cortex and tumor tissues by standard phenol-chloroform extraction techniques. The level of AL-DNA adducts in the renal cortex DNA (10–20 µg) was determined using 32P-postlabeling polyacrylamide gel electrophoresis, as previously described (13 (link)). The TP53-specific mutations were identified using the AmpliChip p53 Research Test (Roche Molecular Diagnostics, Pleasanton, CA), sensitively detecting all single base-pair substitutions and single-base deletions (13 (link)).