Radioimmunoassay for immunoglobulin G autoantibody on the surface of mouse erythrocytes.

A radioimmunoassay (RIA) for the determination of autoantibody on the surface of erythrocytes from New Zealand Black (NZB) mice is described. This method was adapted to hemagglutination plates in order to facilitate the separation of bound and unbound 125I-labeled rabbit anti-mouse immunoglobulin G with an automated cell harvester. Intra- and interday precision, over the useful quantitative range of the standard curve, was 3.9 and 12.9%, respectively. The RIA was five to ten times more sensitive than the direct antiglobulin test which, unlike the RIA, provided little quantitative information on a group of 20 experimental NZB mice. This is publication number 562 from the Department of Basic and Clinical Immunology and Microbiology, Medical University of South Carolina.