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The MinION is a USB-sized version of the new Nanopore DNA sequencing system, which is portable, disposable and will cost less than $900."
Sequencing the first human genome took teams of international researchers a decade to complete. By 2013, a UK-based company thinks it will be able to do it in just 15 minutes.
Last Friday, Oxford Nanopore Technologies unveiled a system that can sequence whole strands of DNA (or its sister molecule RNA) by passing the genetic molecules through small pores in a membrane, called nanopores. The speed and accuracy of the new system rival current sequencing technology.
The company previewed two products to be released later this year: a full-sized unit which can be linked with others for greater computing power, and a miniaturized version that's the size of a USB memory stick. The latter is disposable and will cost less than $900, according to a spokesperson for the company, who said the cheapest current DNA sequencers cost more than $1,000. Such technology could transform diagnostic medicine.
"We could scan patients and see what viruses or bacteria they have," said David Deamer, a professor of biomolecular engineering at UC Santa Cruz, who developed the original idea for the technique more than two decades ago.
DNA, the chemical blueprint inside all our cells, is made up of strings of molecules called nucleotide bases. The sequence of these bases - which come in four types labeled 'A,' 'T,' 'G' and 'C' - encode instructions for making the proteins that perform vital tasks in our cells. In the Nanopore system, an enzyme pulls strands of DNA bases through pores in a synthetic membrane, and an electronic chip senses changes in electrical current as each base blocks a pore.
"It's like sucking a piece of spaghetti through a small hole with a vacuum," said Deamer.
Except the "spaghetti" is being threaded through a hole so narrow you could fit 100,000 of them in the width of one human hair.
Deamer says he first envisioned using nanopore sequencing almost 23 years ago, when he was on the faculty at UC Davis. Geneticist George Church, of Harvard, had come up with the idea in parallel, so Deamer and Church filed a joint patent application, along with Deamer's colleague Daniel Branton, a professor of biology at Harvard.
Meanwhile, physical scientist John Kasianowicz of the National Institute of Standards and Technology and his colleague Hagan Bayley, a chemical biologist, were studying a kind of pore in cell membranes called alpha-hemolysin. Deamer and Branton thought they could use the pore for nanopore sequencing, so a collaboration blossomed. In 2005, Bayley joined biotechnologist Gordon Sanghera to found the company that would become Oxford Nanopore Technologies.
Once the scientists demonstrated DNA could be pulled through nanopores, the next problem was slowing it down enough to read the sequence. That's where Mark Akeson, chairman of the biomolecular engineering department at UCSC, came in. Akeson tried out several different enzymes to find one that dragged the DNA strands through nanopores a thousand times more slowly. Jens Gundlach, a physicist at the University of Washington, provided the next breakthrough, with another kind of pore that would allow only one base through at a time. Oxford Nanopore Technologies refined and commercialized the process.
"We have designed the [nanopore] systems to offer a range of new properties," wrote Sanghera, now CEO of Oxford Nanopore, in an email.
Deamer predicts that in 5 years to 10 years, anyone will be able to have their genome sequenced on a USB stick for a few hundred dollars and bring it to their physician, who will compare it to other genomes and make a diagnosis.
For Oxford Nanopore to fulfill its goal of sequencing an entire human genome in 15 minutes by 2013, 20 Nanopore systems equipped with 8,000 nanopores each would be required, a spokesperson said.
"I think it'll be possible from what I've seen," said Deamer, who is on the company advisory board. "They wouldn't give these promises unless they were pretty confident."
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UK-based company unfurls new technology to sequence whole strands of DNA
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