Conglutinin binding polyethylene glycol precipitation assay for immune complexes

An assay for circulating immune complexes is described which uses radiolabelled bovine conglutinin as ligand and polyethylene glycol precipitation as the technique for separating bound ligands. The technique is simple to perform and gives good sensitivity detecting artificial immune complexes. Its use in detecting complexes in systemic lupus erythematosus and Burkitt's lymphoma is described and it is compared with the Clq binding assay also performed with polyethylene glycol. It is suggested that the simultaneous performance of polyethylene glycol assays using radiolabelled Clq and radiolabelled conglutinin may be an advantageous method for screening sera for the presence of immune complexes.