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Using light to manipulate with DNA

Although nanomedicine keeps on progressing all the time, one thing that scientists weren’t able to develop yet is a “lab on a chip”, which represents a small biological sample which could be carried through microscopic channels for processing. The device would be a portable, fast-acting detector for disease organisms or food-borne pathogens, and it could be used for rapid DNA sequencing and other tests that now take hours or days.

The fact that’s been holding scientists back is that it’s very difficult to move stuff at the nanoscale. But David Erickson, assistant professor of mechanical and aerospace engineering at Cornell, and his colleague Michal Lipson, associate professor of electrical and computer engineering at Cornell, have turned to optofluidics — using the pressure of light to move and manipulate biological molecules.

Their research has shown that light can move and trap molecules as small as 75 nanometers, including DNA molecules. How is this possible? Light is actually a stream of small particles called photons, and they can exert a force, or as waves of expanding and contracting electric and magnetic fields. If light is confined to a waveguide narrower than its wavelength, the wave overflows and can exert a force beyond the guide.

dna-trap-light

The research details are published in the journal Nature. The research was funded by the National Science Foundation.

Source: nsf.gov/news/news_summ.jsp?cntn_id=112942&org=NSF&from=news

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