propertie s and characteristics of an anti-human Chorionic gonadotropin monoclonal antibody.

ABSTRACT

The product of a hybrid cell clone, P3W80, obtained as ascites fluid from mouse peritoneal cavity had high titres of anti human chorionic gonadotropin antibodies e.g. 30 to 40% binding of 125I human chorionic gonadotropin at 107dilution in a radioimmunoassay. The antiserum SB6 (raised against ß human chorionic gonadotropin distributed by National Institutes of Health, USA gave similar binding at 5000 dilution in parallel runs. The monoclonal antibody recognized best human chorionic gonadotropin (0.3 mIU of hormone/tube with B/Bo <75%), but also bound ß and α subunits of human chorionic gonadotropin, 12 and 800 folds lower than human chorionic gonadotropin respectively. No binding was observed with car boxy terminal peptides of β human chorionic gonadotropin ranging from 93 to 145 amino acid residues, indicating the lack of recognition of the C terminal region. No cross reaction with human leutinizing hormone was obtained at the physiological surge levels, a significant competition (B/B0 <75%, obtainable only at 60 mIU of LER 960 human leutinizing hormone/ tube. T h e antibody had heavy chain of IgG1 and light chain of kappa type. It neutralized the bio activity of human chorionic gonadotropin both in vitro and in vivo.