Reading DNA sequences from single molecules of polymerase using nanotechnology

A new nanotech method of DNA sequencing is 30,000 times faster than current DNA sequencing methods. The method, developed by a team at Pacific BioSciences in Menlo Park, California, uses a nanostructured array of thousands of waveguides—tiny hollow metal cylinders, each holding about a zeptoliter (10-21 liter)—to isolate a single molecule of DNA and a single molecule of DNA polymerase. Each of the four nucleotide bases is labeled with a different colored fluorescent label, with the fluorescent dye attached to the portion of the nucleotide that is cleaved and removed after the nucleotide is added to the growing DNA chain. As each nucleotide base is incorporated into the growing DNA chain within one waveguide, a spot of light of the corresponding color first appears, and then disappears. The sequence of flashes in each well reveals the DNA sequence copied in that well in real time. The array allows the simultaneous observation of thousands of single molecule DNA sequencing reactions. Preliminary experiments published in Science (abstract) report 100% accuracy with test DNA templates 150 bases in length. For more, see the article in NewScientist Tech written by Jessica Griggs: “Molecular fireworks could produce ’30-minute genomes’” (thanks to for the link):

So far, the team has built a chip housing 3000 ZMWs [waveguides], which the company hopes will hit the market in 2010. By 2013, it aims to squeeze a million ZMWs [waveguides] onto a single chip and observe DNA being assembled in each simultaneously. Company founder Stephen Turner estimates that such a chip would be able to sequence an entire human genome in under half an hour to 99.999 per cent accuracy for under $1000.

Griggs quotes an independent authority as being skeptical of the 2013 extrapolation. Even for such an elegant technique, it is a long jump from 150 to 3 billion bases.

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