LC/MS‐based Intact IgG and Released Glycan Analysis for Bioprocessing Applications

Robust plate based antibody glycan analysis platforms are urgently needed for biopharmaceutical development and manufacturing as well as for clinical biomarker research. A 96‐well plate based workflow has been developed to analyze both intact IgG antibodies and released N‐glycans using an Orbitrap Fusion Mass Spectrometer and an LC/MS method on the Waters UNIFI platform. Here, such a workflow including protein A purification, PNGaseF digestion, 2‐AB labeling, and SPE clean‐up is described. The measured IgG glycan profile is consistent with that obtained from non‐plate based method and commercial kit and has the advantage of less hands‐on time. Also the application of the workflow in cell culture monitoring and clonal selection work is demonstrated. Apart from checking the major glycan structure changes among clones, post translational modifications (PTMs) such as C‐terminal lysine residue clipping and N‐terminal pyroglutamic acid formation can also be deduced from the workflow. In this plate based workflow, both released glycans and intact IgG are analyzed to allow fast and detailed characterization of biopharmaceuticals on both intact IgG and released glycan levels. The workflow is amenable to automation on a liquid handling platform and suitable for application in bioprocessing to speed up development of biologics.