Only recently has methodology advanced sufficiently to obtain complete
glycosylation profiles of glycoconjugates such as prions or CD34
To briefly summarize today's technology, a plethora of mass
spectrometry (MS) methods are becoming affordable and user-friendly [17,18],
pulsed-amperometric detection methodology is making the separation of
carbohydrates by high-pressure liquid chromatography (HPLC) attractive,
increasingly sensitive nuclear magnetic resonance (NMR) technology is
allowing this powerful technique of structure determination and
identification to be applied to glycoconjugates isolated from natural
sources, and lectins are finding new uses as detection agents for
carbohydrates in chromatography and protein arrays [19-21].
Excellent reviews provide a detailed picture of how different
methodologies are coalescing into a powerful set of tools for
sophisticated and highly sensitive investigation of glycoconjugates [22,23].
While the isolation and characterization of highly complex
glycoproteins are impressive feats, the sobering reality is that only a
handful of the thousands of different glycoconjugates in the human body
have been analyzed so far, which leaves the enormous carbohydrate
diversity of even a single cell unknown in molecular detail. To further
complicate matters, glycosylation profiles are not static, but rapidly
change as cells differentiate, undergo apoptosis, or become diseased.
Today's technologies are inadequate for determining the dynamic
glycosylation profile of a cell and fall well short of the ultimate
goal of glycomics - the evaluation of an entire organism. To dispel the
gloom, however, underlying technologies for innovative, large-scale
glycomic techniques are developing rapidly - both by bringing new
techniques to carbohydrate analysis and by refining established methods
to increase throughput. These two approaches, exemplified by
array-based technologies and the automation of mass spectrometry,
respectively, are discussed below.