Enzyme-linked immunosorbent assay for immunoglobulin G and immunoglobulin A antibodies to Shigella flexneri antigens

An enzyme-linked immunosorbent assay has been developed to detect class-specific antibodies to Shigella flexneri lipopolysaccharide antigens. This enzyme-linked immunosorbent assay system has been used to measure antibodies present in serum or intestinal secretions without further purification. It is considerably more sensitive than passive hemagglutination, allowing detection of as little as 1.3 ng of specific immunoglobulin G antibody per ml in immune sera. Optimal conditions for this assay are outlined in this report.