title: Quantitative two-dimensional ultrastructural distribution of Rh  o (D) antigenic sites on human erythrocyte membranes.
abstract: A method is described for determining the two-dimensional distribution of specific antigens on cell surfaces, and is applied to the D antigen of the Rh antigenic system. Rh-positive human erythrocytes are allowed to react with purified (125)I-labeled human anti-Rh(o)(D) gamma-globulin antibodies, and the sensitized cells are then lysed at an air-water interface. The residual cell membranes are spread flat by surface forces, and are picked up on a carbon-strengthened collodion-coated electron microscope grid. The membranes are then stained with ferritin-conjugated goat antibodies directed against human gamma-globulins. Only Rh-positive cells sensitized with anti-Rh(o)(D) antibodies bind the ferritin-conjugated antihuman gamma-globulins. The ferritin particles are found in small clusters on the membrane surface, and the number of such clusters per unit area agrees with the number of (125)I-labeled anti-Rh(o)(D) antibodies bound per unit area. The Rh(o)(D) antigenic sites appear to be molecularly dispersed on the membrane surface, but in a random two dimensional array.
mesh_terms: D000328:Adult; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000302:isolation & purification; D000937:Antigen-Antibody Reactions; D002462:Cell Membrane / Q000276:immunology*; D002712:Chlorides; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D004912:Erythrocytes / Q000166:cytology / Q000276:immunology*; D005293:Ferritins; D005838:Genotype; D006041:Goats; D006801:Humans; D007120:Immunochemistry; D007455:Iodine; D007456:Iodine Isotopes; D007518:Isoantibodies / Q000302:isolation & purification; D008722:Methods; D008854:Microscopy, Electron; D011817:Rabbits; D012204:Rh-Hr Blood-Group System / Q000032:analysis*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D002712:Chlorides; D007456:Iodine Isotopes; D007518:Isoantibodies; D012204:Rh-Hr Blood-Group System; D005293:Ferritins; D007455:Iodine