Paraformaldehyde-fixed, paraffin embedded (human liver carcinoma); 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 (NOTCH3) Polyclonal Antibody, Unconjugated (SL51148M) at 1:400 overnight at 4°C, followed by a conjugated secondary (sp-0024) for 20 minutes and DAB staining.