Rabbit anti-bovine heart PDH antiserum was raised against El(a, b) isolated from PDC, and then applied to detect Ela and Elb. Appropriate amounis of El were fractionated by SDS-PAGE and electrophoretically transferred to nitrocellulose membrane. The Ela and Elb on the membrane were incubated with anti-El antiserum and identified by GAR-HRP system. It has been found that the immunodetection sensitivity of Ela and Elb were directly proportional to the amount of antigen and transfer time. The lengthy transfer times increased the immunodetection sensitivity of Ela and Elb. The maximal detection sensitivity of Western blotting of Ela and Elb was achieved at 3.5 V/cm for 16-hour transfer under these experimental conditions.