MONOCLONAL ANTIBODY-BASED IMMUNOASSAY OF VITELLOGENIN IN THE BLOOD OF MALE CHANNEL CATFISH (ICTALURUS-PUNCTATUS)

1. A monoclonal antibody to vitellogenin of channel catfish (Ictalurus punctatus) was made, and its specificity was demonstrated using Western blots of serum from female fish, estradiol-treated male fish, untreated male fish, vitellogenin purified by three different methods and egg extracts. 2. An enzyme-linked immunosorbent assay (ELISA), using this monoclonal antibody, detected vitellogenin in the plasma of 59 out of 60 untreated 17-24-month-old male channel catfish with a mean concentration of 338-mu-g/ml and a maximum concentration of 4240-mu-g/ml. 3. Vitellogenin levels in male channel catfish were unrelated to testicular stage, gonadosomatic index and month.