title: Determination of zygosity using flow cytometric analysis of red cell antigen strength.
abstract: A flow cytometry method, developed in our laboratory to measure red cell (RBC)-bound IgG, was compared to the manual titration technique in the measurement of RBC antigen strength to determine zygosity. Parallel studies using antibodies to antigens in the Rh, Kell, Kidd, Ss, and Duffy systems were performed. The antisera (n = 20) were tested against five examples each of RBCs from apparent homozygotes and heterozygotes. The flow cytometry method was clearly superior, showing distinct differences, with no overlap of the ranges of results, between the reactions of RBCs from homozygotes and heterozygotes with 10 of 20 (50%) antisera. By the manual titration technique none of these sera clearly demonstrated dosage and 15 showed overlap of the ranges. It was obvious from the results that the commonly used manual titration technique for comparing the test RBCs with a single example of RBCs from a homozygote and heterozygote yielded inaccurate results.
mesh_terms: D001789:Blood Group Antigens / Q000235:genetics* / Q000276:immunology; D004303:Dosage Compensation, Genetic; D005434:Flow Cytometry; D006580:Genetic Carrier Screening / Q000379:methods; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007626:Kell Blood-Group System / Q000235:genetics / Q000276:immunology; D007667:Kidd Blood-Group System / Q000235:genetics / Q000276:immunology; D008951:MNSs Blood-Group System / Q000235:genetics / Q000276:immunology; D012204:Rh-Hr Blood-Group System / Q000235:genetics / Q000276:immunology
chemical_list: D001789:Blood Group Antigens; D007074:Immunoglobulin G; D007626:Kell Blood-Group System; D007667:Kidd Blood-Group System; D008951:MNSs Blood-Group System; D012204:Rh-Hr Blood-Group System