Immunogold probe for the light-microscopic phenotyping of human mast cells and basophils

A method is presented whereby light microscopic phenotyping of human basophils and lung mast cells was obtained by simultaneous labeling of surface antigens with specific mouse monoclonal antibodies and an anti-mouse IgG immunogold probe and histochemical staining with alcian blue, a highly specific stain for these cells' granules. The double labeling technique offers a useful immunohistochemical method for the phenotyping of basophils and mast cells in impure cell preparations. The procedure is relatively simple and requires small cell samples while providing accurate information on functional and differentiation markers. Preliminary results of human lung mast cell and peripheral blood basophil phenotyping discloses class I histocompatibility antigens on both cell types and class II antigen HLA DR on 10-20% of mast cells alone. Lung mast cells also unexpectedly exhibit the leukocyte marker HLE-1.