Therapeutic monoclonal antibodies (mAbs) are glycoproteins produced by living cell systems. Glycosylation is one of the most common post-translational modifications (PTMs) of proteins. The glycan moieties attached to the proteins can directly affect protein stability, bioactivity, and immunogenicity. Therefore, glycan variants of a glycoprotein product must be adequately analyzed and controlled to ensure product quality. However, the inherent complexity of protein glycosylation, combining the vast diversity in glycan structure and composition add an additional level of daunting analytical challenge.

https://www.creativebiolabs.net/glycosylation-analysis-of-therapeutic-glycoproteins.htm