Glycans are vital components of glycoproteins, glycolipids, and proteoglycans in all domains of life. Glycosylation occurs co- or post-translationally on >50% of eukaryotic proteins resulting in membrane-associated, intracellular, or secreted glycoproteins that are crucial in cellular processes, protein bioactivity and metabolic turnover. Intracellular glycans mediate protein folding, stability, and trafficking while at the cell surface, they participate in recognition, cell-cell interactions involved in adhesion, migration, and embryonic development; host-pathogen interactions critical for bacterial and viral infections; and initiation of immune response. Aberrant glycosylation profiles correlate with inflammation and are universal feature of cancer, with sialic acids playing an especially prominent role as tumor associated carbohydrate antigens (TACAs). Altered sialylation of tumor cell surfaces is associated with several critical malignant properties that include invasiveness and metastatic potential suggesting its implication in clinical diagnosis. Since glycoproteins are not directly encoded in the genome, methods of characterization and analyses of glycoproteins are of great interest.