Immunobead enzyme-linked immunosorbent assay for quantitating immunoglobulin A in human secretions and serum

We have developed an enzyme-linked immunosorbent assay for quantitating human immunoglobulin A in human secretions and serum. The procedure uses Immunobeads as the solid phase, has a sensitivity of 10 ng/ml, and can be completed in 1 day. Since there is no diffusion through agar, the assay does not require a correction factor when measuring secretory immunoglobulin A. This method should be useful in studies of local mucosal immunity in humans, especially when a very sensitive assay is needed.