CA isoforms in mouse heart. Total heart tissue membranes containing 50 μg protein from wild-type (WT), CA IV KO, CA XIV KO, and CA IV/CA XIV KO mice were analyzed by SDS-PAGE followed by Western blot using αCA IV, CA IX, CA XII, and CA XIV antisera, and preimmune serum for CA IX. Polypeptides for CA IV, CA IX, CA XII, and CA XIV are indicated. Preimmune serum for CA IX did not show any reaction.