title: Intracellular marking of skeletal muscle cells with horseradish peroxidase in combination with a stain for cholinesterase.
abstract: A procedure is described by which muscle fibers can be electrophysiologically studied, intracellulary marked with horseradish peroxidase (HRP), and stained for acetylcholinesterase (AChE) activity to identify nerve endings. Following electrophysiological characterization, 4% HRP is injected through the recording microelectrode with small depolarizing pulses. Muscles are fixed, washed, and stained with a Koelle procedure for AChE modified by extending the incubation period to 15 hours to identify small nerve endings. The HRP is visualized with 3,3'-diaminobenzidine tetrahydrochloride or benzidine dihydrochloride. Stained muscles are embedded in Epon and sectioned. Lucifer yellow dye is also demonstrated to be an excellent intracellular marker of muscle fibers but it cannot be combined with AChE staining.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis*; D000818:Animals; D003584:Cytological Techniques; D006735:Horseradish Peroxidase; D009469:Neuromuscular Junction / Q000201:enzymology / Q000648:ultrastructure*; D009801:Oculomotor Muscles / Q000166:cytology* / Q000502:physiology; D010544:Peroxidases; D051381:Rats; D013194:Staining and Labeling / Q000379:methods
chemical_list: D006735:Horseradish Peroxidase; D010544:Peroxidases; D000110:Acetylcholinesterase