Faster DNA Analysis at Room Temperature

Faster DNA Analysis at Room Temperature

A palm-sized biochip for room temperature DNA detection developed by
Paul Li at Simon Fraser University near Vancouver, Canada. The 4"
diameter chip is roughly the same thickness as the Canadian one dollar
coin, the Loonie (shown in the picture for scale). (Credit: American
Institute of Physics)

ScienceDaily (Aug. 3, 2010) — DNA microarrays are one of the most
powerful tools in molecular biology today. The devices, which can be
used to probe biological samples and detect particular genes or
genetic sequences, are employed in everything from forensic analysis
to disease detection to drug development.

Now Paul Li and colleagues at Simon Fraser University in Burnaby,
Canada have combined DNA microarrays with microfluidic devices, which
are used for the precise control of liquids at the nanoscale. In an
upcoming issue of the journal Biomicrofluidics, which is published by
the American Institute of Physics (AIP), Li and his colleagues
describe how the first combined device can be used for probing and
detecting DNA.

The key to Li's result: gold nanoparticles. Suspended in liquid and
mixed with DNA, the nanometer-scale spheres of gold act as mini
magnets that adhere to each of the DNA's twin strands. When the DNA is
heated, the two strands separate, and the gold nanoparticles keep them
apart, which allows the single strands to be probed with other pieces
of DNA that are engineered to recognize particular sequences.

Li, whose work is funded by the Natural Sciences and Engineering
Research Council of Canada, is applying for a patent for his
technique. He sees a host of benefits from the combination of DNA
microarrays and microfluidics.

"It's faster and requires a relatively small sample," he says, adding
in his paper that "the whole procedure is accomplished at room
temperature in an hour and apparatus for high temperature… is not