Charge heterogeneity of HLA-B15 and HLA-B5 complexes was analyzed by one-dimensional isoelectric focusing (1D-IEF). Frozen peripheral blood lymphocytes were metabolically labeled with 35S methionine. The class I antigens were immunoprecipitated with monoclonal antibody 4E, which detects a determinant shared by HLA-B locus and Aw19-complex antigens. The desialated 1D-IEF banding patterns were correlated to microcytotoxicity data of a panel of donors from a variety of racial groups. Serologic analysis indicated the presence of specific variants: Te76, Te78, and Te79. 1D-IEF analysis clearly showed polymorphism in the B15 and B5 complexes. The Bw62 associated variant Te79 exhibited bands distinct from Bw62. One Bw62 typed donor produced a band that was different from other Bw62 typed cells. A migration pattern difference was discovered between blacks and Caucasians that were typed Bw57. Investigated antigens included HLA-B35, w46, 51, w52, w53, w57, w58, w62, w63, w70, Te76, Te78, and Te79.