How do you control glycosylation patterns in mammalian cell culture?

Glycosylation control involves understanding and manipulating the factors affecting glycan structures. Process parameters: temperature (lower temperature often increases galactosylation), pH (affects enzyme activities), dissolved oxygen, osmolality, and culture duration. Media components: manganese (essential for galactosyltransferases), uridine/galactose supplementation, and amino acid levels. Feed strategies: timing and composition of feeds affect glycosylation. Cell line factors: expression level, clonal selection, and genetic engineering (overexpression of glycosyltransferases). Analytics include HILIC, CE, mass spectrometry for glycan profiling. Understanding cell line capabilities and process design space enables specification of consistent glycoform distributions. Glycosylation affects efficacy, half-life, and immunogenicity.