Fig. 2: Combined extracted ion chromatogram (EIC) for 140 observed Spike protein glycopeptides.

Combined extracted ion chromatogram (EIC) for 140 observed Spike protein glycopeptides separated by 60-min reverse-phase LC–MS run showing peak resolution for peptides of different sequence, and also different glycoforms of the same peptide, which are unresolved and coelute within a 4-min retention time window. Peak volume (area) can be used to estimate the relative abundance of each glycopeptide species.