Structures of LacNAc and poly-LacNAc glycosphingolipid glycans from human leukocytes. The glycans of monosialo GSLs from human neutrophils were enzymatically released using ceramide glycanase, permethylated, and then subjected to total ion mapping MS and MSⁿ. The structures of the most abundant 99% of species in the sample are shown in symbol format.⁴⁴  Structure abbreviations (n/m) are defined in Figure 1 legend.