Oligosaccharides play a crucial role in many of the recognition, signaling,
and adhesion events that take place at the surface of cells. Abnormalities
in the synthesis or presentation of these carbohydrates can lead to misfol
ded and inactive proteins, as well as to several debilitating disease state
s. However, their diverse structures, which are the key to their function,
have hampered studies by biologists and chemists alike. This review present
s an overview of techniques for examining and manipulating cell surface oli
gosaccharides through genetic, enzymatic, and chemical strategies.