MALDI-TOF MS of purified human leukocyte monosialoglycosphingolipids. The monosialo GSL fraction from human leukocytes was subjected to MALDI-TOF MS. Peaks corresponding to masses of glycosphingolipids 110 mass units separated, reflecting the presence of the same glycan species bearing either C16:0 or C24:1 fatty acid amides, are indicated. The proposed structures are abbreviated as n/m where n is the number of LacNAc repeats and m the number of fucoses in the general structure NeuAcα2-3[Galβ1-4(Fucα1-3)_0-1GlcNAcβ1-3]_nGalβ1-4GlcβCer. The inset structure, 3/1, was isolated from human leukemia cells and contains 3 LacNAc repeats (one of which is fucosylated) and the VIM-2 structure¹⁹  (International Union of Pure and Applied Chemistry [IUPAC, Research Triangle Park, NC] designation: VIII³NeuAcV³Fuc-nLc₈Cer).