Immunohistochemical analysis of paraffin-embedded Human-lung tissue. 1,CD23 Monoclonal Antibody(1E9) was diluted at 1:200(4°C,overnight). 2, Sodium citrate pH 6. was used for antibody retrieval(>98°C,2min). 3,Secondary antibody was diluted at 1:100(room tempeRature, 30min). Negative control was used by secondary antibody only.