Epitopes immunologically related to glycophorin a on human malignant and non‐malignant cells in culture

Nine monoclonal antibodies specific to different antigenic determinants on the cyanogen bromide fragments CNBr3 (1‐8) and CNBrl (9‐8l) of glycophorin A, the major sialoglycoprotein of human red blood cells, were used for the detection of similar or cross‐reactive epitope(s) on nucleated somatic cells. A panel of human malignant and non‐malignant cells consisting of erythroleukemia, melanoma and carcinomas of breast, cervix, larynx, nasopharynx and colon, as well as human fibroblasts and mammary cells, were tested using a sensitive enzyme‐linked immunoassay. The presence of glycophorin‐like epitopes were demonstrated, in varying concentrations, on all cells tested. These epitropes were found to be localized on the cell membranes by indirect immunofluorescence.