The glycolipids of human teratocarcinoma-derived cell line NCCIT were compared with those of 5 murine teratocarcinoma-derived cell lines. Glycolipid antigens were identified by cell surface immunofluorescence and high-performance thin-layer chromatography (HPTLC) immunostaining with a panel of monoclonal anti-carbohydrate antibodies. Human NCCIT embryonal carcinoma (EC) cells contained extended globo-series glycolipids Gb5 (galactosyl globoside) and GL7 (sialyl galactosyl globoside) recognized by antibodies to stage-specific embryonic antigens 3 and 4 (SSEA-3 and −4). SSEA-4 was not detected by immunofluorescence on the surface of any of the 5 murine teratocarcinoma-derived cell lines examined; however, SSEA-3 was detected on the surface of murine cell lines resembling primitive endoderm (JC44, NF-PE) and trophectoderm (E6496D). HPTLC analysis revealed a large amount of globoside (Gb4) in these differentiated cells, which may account for their labeling with anti-SSEA-3 antibody. Globo-series glycolipids were also detected in murine EC cells; however, differences were noted between the 2 cell lines examined. F9 cells contained primarily Gb4 and Forssman glycolipid, whereas NF-I cells contained only minor amounts of Gb4 and lacked Forssman glycolipid entirely. Our results, coupled with the known distribution of Forssman antigen in the egg cylinder-stage mouse embryo, suggest that F9 and NF-I murine EC cells are replicas of cells at different stages of development of the embryonic ectoderm. Glycolipids of normal mouse embryos were examined for comparison. Gb4 and Forssman glycolipid were present in both embryonic and extra-embryonic tissues, whereas Gb5 and GL7 were restricted to visceral yolk sac and placenta. Our results demonstrate that human and murine teratocarcinoma-derived cells both synthesize extended globo-series glycolipids; however, oligosaccharide chain elongation takes different pathways in the 2 species. These differences reflect species-related and cell type-specific patterns of glycosylation.