A biotin-labelled antigen radioimmunoassay (BILA) for antibodies to membrane antigens useful for monoclonal antibody screening.

Viable cells or protein extracts were labelled with N-hydroxysuccinimidobiotin and used as target antigens in a biotin-labelled antigen radioimmunoassay (BILA). The binding of the biotinylated antigens to capture antibodies coated on the bottoms of 96-well plastic plates were measured using 125I-labelled streptavidin as the detection step. The assay circumvents some of the problems associated with solid-phase RIA and permits screening of antibodies to undefined protein antigens present in very small amounts in complex protein solutions.