An enzyme-linked immunosorbent assay (ELISA) was developed for screening production of monoclonal antibodies with specificity for surface membrane components on human mononuclear cells. Whole cells used as antigen were dessicated under vaccum in flexible polyvinyl chloride plates or in rigid plates coated with protein-detergent solution. Rabbit or goat anti-mouse IgG conjugated with peroxidase was used as indicator after affinity column purification. Under these conditions, the sensitivity of ELISA proved comparable to other binding techniques or microcytoxicity and allowed rapid, reproducible, and efficient detection of antibody producing hybridomas.