title: Use of monoclonal antibody and colloidal gold in E.M. localization of von Willebrand factor in megakaryocytes and platelets.
abstract: The subcellular localization of Factor VIII/von Willebrand protein (VIII R:Ag) is studied with monoclonal antibody and gold immunocytochemical technique. Monoclonal antibody against purified VIII R:Ag is brightly fluorescent on megakaryocytes and platelets. In E.M., gold immunolabeling is performed on thin cell sections of human megakaryocytes and platelets. Different embedding materials are used to preserve the antigenicity : Epon embedded megakaryocytes show a high concentration of VIII R:Ag in alpha-granules using 4F9 monoclonal antibody. In comparison, lowicryl K4M embedded material does not improve the same specificity, only a few platelets granules were stained. This subcellular localization, in full agreement with biochemical results appears visualized for the first time in E.M.
mesh_terms: D000911:Antibodies, Monoclonal; D001779:Blood Coagulation Factors / Q000276:immunology*; D001792:Blood Platelets / Q000378:metabolism*; D005169:Factor VIII / Q000378:metabolism; D006046:Gold; D006651:Histocytochemistry; D006801:Humans; D008533:Megakaryocytes / Q000378:metabolism*; D008854:Microscopy, Electron; D014841:von Willebrand Factor / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D001779:Blood Coagulation Factors; D014841:von Willebrand Factor; D006046:Gold; D005169:Factor VIII