A solid-phase bead radioimmunoassay has been developed for measuring IgE against antigen E (IgE-a-AgE) in serum. The patient's IgE is bound by monoclonal mouse anti-human IgE which is on the surface of a solid bead. Other immunoglobulin classes are not bound and can be washed away. Radiolabeled AgE is then added and is specifically bound by IgE-a-AgE. This assay is reproducible, and in contrast to specific IgE assays utilizing RAST methodology, it cannot be inhibited by specific antibody of other classes. Moreover, the solid-phase bead method does not utilize myeloma IgE. Finally, its results correlate well with those of a previously developed polystyrene tube method.