A solid-phase radioimmunoassay for detecting antibodies to brain cell surface antigens.

A trace radioimmuno-binding assay is described which utilizes microcultures of dissociated cerebellar cells from neonatal mice as targets for the binding of antibodies to surface antigens on normal brain cells. This microassay is easy to perform, highly sensitive and economical in terms of cells and antibodies. Results are presented showing its specificity for antigens accessible at the cell surface. For the assay, dissociated cells are cultured in polylysine-coated wells of 60-well Terasaki microtest plates. After a recovery period allowing extensive outgrowth of neurites, the cultures are incubated with antibody solution, and bound antibody is revealed by an iodinated second antibody. This monolayer binding assay is particularly suited to the screening of large numbers of samples, for instance when trying to raise monoclonal antibodies against brain cells by the hybridoma methodology. The test can also be used for the analysis of anti-surface specificities in conventional antisera.