Paraformaldehyde-fixed, paraffin embedded Human brain; Antigen retrieval by boiling in sodium citrate buffer (pH6.0) for 15min; Block endogenous peroxidase by 3% hydrogen peroxide for 20 minutes; Blocking buffer (normal goat serum) at 37°C for 30min; Antibody incubation with CHRM2 Monoclonal Antibody, Unconjugated (bsm-51598M) at 1:25 overnight at 4°C, DAB staining.