DNA and proteins are the stars of biotech, but they aren't the only prime players in biology. Recent studies show that complex sugars called polysaccharides have a critical role in cell development and tumor formation. Like DNA, these sugars are composed of basic chemical building blocks whose sequence determines their biological functions. Until now, however, sugars have remained a bit player in the biotech revolution-partly because sequencing a single polysaccharide could take months.

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