Raji-K562 hybrids and their use for trioma production

Cells from the B lymphoblastoid cell line Raji (Burkitt lymphoma) and from the myeloid-erythroid cell line K562 (subline AB5), stained by two different fluorochromes, were fused in vitro by means of PEG. Hybrid cells exhibiting heterofluorescence were isolated in a cell sorter (FACS III). They were cloned and analyzed for both Raji and K562 derived antigens. Hybrid cells retained the excellent growth behaviour of AB5 cells while expressing also Raji antigens. One of the hybrids (BD7) was used for trioma production when fused with human stimulated spleen cells. Trioma cells representing a fusion product of three parental cells may be useful for studying problems of gene regulation and expression.