Abstract
We describe a simple indirect immunohistochemical method for localization of acetylcholine receptors (AChR) in motor endplates at the light and electron microscopic level. This method involves the use of a monoclonal antibody directed against the main immunogenic region (MIR) of AChRs and is applicable to periodate-lysine-paraformaldehyde (PLP)-fixed tissue. We discuss the advantages of this method, as compared with the alpha-bungarotoxin-immunoperoxidase technique, and stress its value for diagnostic investigations of motor point biopsies from patients with neuromuscular transmission disorders.