The ganglioside patterns from a representative collection of 20 human B-cell, T-cell, null cell, myeloid cell, and early erythroid cell lines were determined. Radioactive sugar-labeled gangliosides from cultured cells were extracted, analyzed, and quantitated by high-performance thin-layer chromatography (HPTLC) and high-pressure liquid chromatography, essentially according to the polarity of the oligosaccharide chain. The ganglioside labeling patterns of the human cell lines were in some cases extremely complex, since more than 100 components could be separated upon two-dimensional HPTLC, e.g., in the case of a promyelocytic cell line. Each type of cell showed a characteristic pattern: Null cell lines were much less complex than T-cell lines, and myeloid and erythroid lines exhibited characteristic patterns as well. Although clearly distinguishable from all other cell lines, the B-cell lines showed a high degree of heterogeneity. Therefore, gangliosides can be expected to serve as additional markers to establish the origin, of a cell line or to classify pathologic cell populations.