MONOCLONAL ANTIBODIES TO HUMAN ALPHA-FETOPROTEIN

Alpha-fetoprotein (AFP), a serum glycoprotein belonging to the onco-developmental proteins group, serves as a marker both in cancer research and in studies concerning fetal development and fetal pathophysiology. Monoclonal anti-AFP antibodies are essential reagents in developing appropriate techniques for measurement of this protein. In this study, in order to produce anti-AFP monoclonal antibody (mAb), AFP was partially purified from cord sera using two-step ion-exchange chromatography on DEAE-cellulose with a final recovery of about 570µg. MAbs against this preparation was raised by hybridoma technology using Ag8.653 mouse myeloma cells as the fusion partner. Hybridomas appeared in 10% (30/300) of culture wells and of these 2 clones were found to be positive for anti-AFP production. In western blot analysis a 70 kD band from dead fetus serum-but not adult serum-was stained by both mAbs. A sandwich ELISA technique using polyclonal antisera on one side and mAbs on the other side was employed to plot dose response curves. The positive dose dependent reactivity of the mAbs with standard AFP and other AFP containing samples and the negative reaction with normal adult sera lacking AFP showed the specificity of the mAbs for AFP.