Invention's bit of gold goes a long way

(PhysOrg.com) -- A Simon Fraser University chemist who pioneered lab-on-a-biochip technology six years ago has struck gold in the research world again, this time literally.

Paul Li has combined nanoscale-sized-particles of gold with two powerful tools in molecular biology to make DNA analysis more than 10 times faster at room temperature, rather than previously required higher temperatures.

Li has sped up gene identification by fusing the slide-like microarray’s ability to identify known DNA gene sequences with the multi-channel microfluidic device’s ability to quickly analyse small amounts of liquid.

The palm-sized hybrid biochip is roughly the same thickness as the Canadian Loonie.

But what really makes the invention a biomedical gold mine is the addition of gold nanoparticles to the liquid being analysed on it. Mixed with DNA, tiny 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. The gold nanoparticles keep them apart, which enables scientists to probe each strand with other pieces of DNA that are engineered to recognize known gene sequences.

“The key benefit of the gold is that it allows us to do our analysis at room temperature (25 degrees C),” explains Li. “That is half the conventional temperature needed, which requires the use of an apparatus that tolerates high temperatures.

“More importantly, DNA sequences with slight differences are now differentiated by the nanoparticle, but not by the high temperature.”

This invention will revolutionize researchers’ ability to probe biological samples and detect genes for forensic analysis, disease detection and drug development.

In 2004, Li produced the world’s first lab-on-a-biochip for single cell measurement. Only half the size of a credit card, the tiny lab is equipped with channels for separation and analysis of individual cells, and a chamber to test compounds on them.

Provided by Simon Fraser University