| Abstract: | The development of monoclonal antibodies has allowed characterization of subpopulations of lymphoid cells and of their in situ distribution in tissues. The feasibility of simultaneous localization of two surface antigens was studied by double staining with monoclonal antibodies to B cells, T cell subsets and follicular dendritic reticulum cells (DRC) using the avidin-biotin-complex (ABC) method in sections of human lymphoid tissues (tonsil, lymph node, spleen) and a non-lymphoid tissue, endometrium. Color mixture was avoided when an additional incubation with avidin-biotin-labeled peroxidase and subsequent development in the respective substrate of the first sequence preceded the second staining sequence using the primary antibodies at optimal concentrations. The antigenic profiles were portrayed by contrasting and distinct colors of the reaction products. It was observed that T lymphocytes of the cytotoxic/suppressor and helper/inducer phenotypes were topographically associated with each other and with B cells in B and T cell areas of lymphoid tissues as well as in lymphocytic aggregates in endometria. Subpopulations of these cells were mantled by processes of DRCs in lymphoid follicles. The findings indicate that the double ABC staining method can be used for simultaneous demonstration of two surface antigens in tissue sections. |
