Radioimmunocytochemical localization of retinal S-antigen with monoclonal antibodies.

Two monoclonal antibodies (RSA1/83 and RSA2/83) were developed against a homogeneous preparation of bovine retinal S-antigen. The two hybridomas produced by mouse X mouse hybrid myeloma cells secrete immunoglobulin G. Indirect autoradiography on glutaraldehyde-fixed preparations of bovine explants was used to locate the antigenic site. Antibody RSA1/83 recognizes the antigen primarily in the apical region of the rod outer segment, while antibody RSA2/83 located the antigen both in the outer and inner segments of the rod photoreceptor cells. A distinct band of silver grains also appeared along the inner limiting membrane with both antibodies. Control explants showed no specific labeling pattern over the various retinal compartments.