MS/MS fragmentation patterns of dabsylated glycopeptide products in the range of m/z 900–2800 are shown. In the lower mass range, presence of the diagnostic fragment ion at m/z 1111 in AgFucTA and AgFucT6 products are indicating the presence of core fucose (A–C), which is absent in Lewis-type AgFucTC products (D–F). In case of the dabsylated GnGnF3F6 product, a diagnostic fragment of m/z 1257 was observed indicating a difucosylated N-glycan core (C). Terminal loss of one fucose residue from the parent ion (loss of m/z 146) was observed for all products, whereby in AgFucTC products loss of either ‘en-block’ Hex1HexNAc1, indicated by the loss of m/z 365 (D) or ‘en-block’ loss of two HexNAc residues, indicated by the loss of m/z 407 (E, F) were detected. The assumed fragmentation pattern with loss of the α1,6 mannose arm is based on previous observations for N-glycans. Asterisks represent unidentified signals.