Generation of monoclonal antibodies to human prolactin and applications in solid-phase immunoassays

Monoclonal antibodies specific to human prolactin were generated by an improved hybridoma technique. Following immunization with hormone conjugated with hemocyanin and cell fusion, hybrid cells were first cultured in a semisolid medium containing methylcellulose and later transferred to liquid medium for subculture. Out of 1500 colonies that were initially recovered in one single cell fusion experiment, 300 were shown to exhibit affinity to human prolactin by enzyme-linked immunosorbent assay and radioimmunoassay. Finally, nine monoclonal antibodies having high affinity and specificity to human prolactin were selected for further evaluations. From the results of a cross-matching procedure, one pair of antibodies reacting with discrete antigenic determinants of human prolactin was identified. Using a pair of monoclonal antibodies, the solid phase sandwich immunoradiometric assay and enzyme immunoassay were designed. The sensitivity of these 1-h immunoassay procedures for the determination of human prolactin was 2 ng/ml.