Deciphering the glycocode: the complexity and analytical challenge of glycomics

Carbohydrates coat most types of cell in nature and are intimately involved in various biological events, including cell differentiation, homing to specific tissues, cell adhesion, cell recognition, microbial pathogenesis and immunological recognition. Carbohydrate structures are complex to analyze owing to their branched nature, the diversity of secondary modifications of monomers, their indirect relationship to the genome and the range of molecular contexts in which the modifications are found. Thus, whereas the fields of genomics and proteomics have become accessible to most scientists, technologies to assess glycan structures rapidly (i.e. glycomics) are still in the developmental stages. This review focuses on recent developments in glycomic technologies, including new high-throughput techniques for glycan purification and annotation that are advancing mass-spectrometry-based glycomics, and the latest work on microarray methodologies to decipher the glycome.