Table 1. Quantification of the N-glycosylation site occupancy.

	Secreted mAb		ER-retained mAb
Glycosylation site occupancy	% of glycosylation based on ion intensities	% of glycosylation based on densitometry	% of glycosylation based on ion intensities	% of glycosylation based on densitometry
EEQYDSTYR	77	80	70	68
EEQYNSTYR	23	20	30	32

The N-glycosylation site occupancy was calculated from the comparison of the ion intensity of the non-glycosylated versus deglycosylated peptides using single and discharged specific ions and from densitometry analysis of the two bands corresponding to heavy chains observed on the NuPAGE gel.