Determining N-glycan Structures by HILIC-MS
Aliquots (1 µL) of the unlabeled portion of N-glycans released from
samples were taken for permethylation analysis along with negative and
positive controls (buffer, water, and fetuin). Unlabeled glycan samples
were permethylated using methyl iodide in a dimethylsulfoxide
(DMSO)/NaOH suspension for in-solution permethylation of glycans.
Permethylated glycans were obtained from solution by extracting with
chloroform, and samples were run on a Shimadzu-Biotech Resonance MALDI
mass spectrometer using 10 mg/mL 2,5-dihydroxybenzoic acid (DHB) in
acetonitrile as the matrix.