The analysis of glycosylation: a continued need for high pH anion exchange chromatography.

An appreciation of the structures of the oligosaccharide chains which become attached to biomolecules (the process known as glycosylation), and their relevance to the biological function of the molecule concerned, has progressed rapidly in recent years with developments in site-selective protein glycosylation, oligosaccharide synthesis and in vivo targeting of oligosaccharides. These developments have necessitated the parallel development of effective analytical tools for the determination of the structures of glycosylation. The conclusion of studies in the 1980s and 1990s was that high pH anion exchange chromatography (HPAEC) was the most effective HPLC mode for the analysis of glycosylation. It allowed the fractionation of complex mixtures of monosaccharides or oligosaccharides, the latter in terms of charge, size, composition, anomerity and intra-chain linkages. This review reinvestigates whether HPAEC still appears to offer the most effective means of analysing glycosylation.