Radioimmunoassay on polycarbonate membranes: a sensitive and simplified method for the detection and quantitation of antibody.

A new radioimmunoassay technique is described in which a sampling manifold and polycarbonate filter membranes are used. Antigen-antibody reactions take place on the membranes. The manifold permits the simultaneous running of 30 samples and a rapid wash technique in which the washing solution is introduced into the manifold wells and suctioned off from below. The polycarbonate membrane offers a distinct advantage over the cellulose acetate in that nonspecific protein adsorption is substantially reduced. Antigens employed are whole bacteria or soluble antigen coupled to Sepharose beads and are layered over the membrane surface. A radiolabeled antibody is used to measure the primary antigen-antibody interaction. The sensitivity of the procedure is equal to that of fluorescent antibody tests.