A, representative genotype analysis of wild type and Ephx2-null mice from the NIH colony. Negative and positive controls show no band product or a 290-bp band, respectively. Genomic DNA of sEH amplified from mouse tail shows a 290-bp gene product of sEH from NIH colony wild type. The Ephx2-null mice show a higher gene product of 560 bp from the neomycin resistant gene. Genotypic analysis was performed in all mice in each breeding colony. B, tissue distribution of sEH protein from wild type and Ephx2-null mice from both colonies. Immunoblots demonstrate expression of the 62.5 kDa protein in heart (H), kidney (K), and liver (L) of wild type (+/+) and lack of sEH protein expression in Ephx2-null mice (−/−) of both colonies.