NP-HPLC chromatograms of 2-AB-labeled N-glycans released enzymatically with PNGase F from HCs of mAbP and mAbM. The schematic glycan structures of the main peaks found in N-glycan pools from mAbP (Upper) and mAbM (Lower) are indicated. All peaks were numbered, and corresponding glycans were assigned by using an array of exoglycosidase enzymes and confirmed by MALDI-TOF mass spectrometry. The symbols of the glycan structures are: filled square, GlcNAc; open circle, mannose; open diamond, galactose; diamond with a dot, fucose; filled star, sialic acid; open triangle, xylose; dotted line, α-linkage; solid line, β-linkage; λ, 1–2 linkage; /, 1–3 linkage; –, 1–4 linkage; \, 1–6 linkage; ∼, undetermined linkage.