A solid-phase chemiluminescence immunoassay for determination of IgG in eluates of psoriatic scales.

Abstract A solid-phase chemiluminescence immunoassay for determining immunoglobulin G (IgG) in eluates of psoriatic scales is described. Polystyrene balls coated with protein A bound the IgG present in the eluates and in human sera. The bound IgG was then detected by a luminol-coupled goat anti-human IgG conjugate, characterized for antibody, protein and luminol content. This method correlated well with radial immunodiffusion in determining IgG levels in human sera ( r = 0.97). The sensitivity of the assay was 0.5 μg IgG. Eluates prepared from psoriatic scales treated sequentially with buffers of decreasing pH all contained IgG when tested by this method. pH 2 eluates, however, contained more IgG than pH 3 eluates, suggesting the presence of specifically bound antibodies.