Immunohistochemical demonstration of T-lymphocyte subsets in tissue sections using monoclonal antibodies: a 3-layer PAP system and comparison of three immunoperoxidase methods

Several immunohistochemical systems have been described to study T cells and their subsets in cryostat sections using monoclonal antibodies. In this report tonsils were studied by 2-layer and 4-layer immunoperoxidase techniques. In addition a 3-layer immunoperoxidase method using mouse PAP is proposed. The 2-layer technique proved unsatisfactory due to insufficient sensitivity. The other methods were characterized by comparably high sensitivity. The mouse PAP 3-layer system gave the most specific results due in particular to the complete absence of immunoglobulin staining in the germinal centers.