Most gene sequencers require thousands of copies of a DNA strand. But Helicos BioSciences' new system can sequence a single molecule, simplifying sample preparation and decreasing cost. It can also gauge gene activity by counting messenger RNAs, molecules that help translate genes into proteins; its ability to rapidly determine chemicals' effects on gene activity could speed drug development. With improvements to just its reagent kits, the system could ultimately deliver the $1,000 genome.

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