For frozen section IHC staining, you don’t need doing antigen retrieval (e.g. citrate buffer/microwave oven or high pressure cooker-heat) or enzyme digestion for most anti CD3, CD4 or CD8 antibody. But please use good monoclonal antibody with optimal concentration. I recommend you use BD Biosciences Pharmingen’s antibody. If you need order antibody, please contact BD China (Beijing). After IHC staining, you can do PAS or other staining for your basal membrane.