[The development of an immunoenzyme method for determining human secretory IgA].

The results of the work on the development of an enzyme immunoassay (EIA) system for the determination of secretory IgA (S-IgA) are presented. A first, S-IgA was isolated from human colostrum and used as the basis for obtaining biologically active immunosorbent; then antibodies to S-IgA were isolated and the specific conjugate was obtained. The determination of S-IgA was carried out by the method of sandwich EIA. The newly developed EIA system permitted the determination of S-IgA only, giving no positive reactions with serum immunoglobulins. The data thus obtained make it possible to regard this assay system as specific, sensitive and suitable for further trials.