Enzyme-linked immunosorbent assay of mouse interleukin-2 receptors

An enzyme-linked immunosorbent assay (ELISA) which measures soluble mouse interleukin-2 receptor (IL-2R) was developed, using two monoclonal anti-mouse IL-2R antibodies directed against two different epitopes of the IL-2R molecule. The ELISA-reactive material was identical with the IL-2R material which was capable of binding to affinity support beads coupled with recombinant interleukin-2 (IL-2). Quantitation of IL-2R in detergent-lysed cells was compared to that of the purified IL-2R, and the detection limit was estimated to be within the range of 2-10 ng/ml of a test sample. This sensitivity made it possible to determine soluble IL-2R levels in cell culture supernatants and mouse sera.