Da mass ship on pepNdes containing lysine residues. It is normally detected in pepNde containing missed cleavages, as glycaNon inhibits trypsin acNvity . GlycaNon is a common and important PTM that can occur during the manufacturing and storage of therapeuNc proteins, including mAbs and fusion proteins. Its effects should be evaluated and can differ from molecule to molecule . GlycaNon was observed for K146 and modificaNon rates were comparable between the four commercial DP batches and DS reference material, with the abundance levels ranging between 0.07% and 0.08% as visualised in Figure .