for National Geographic News
A new discovery could lead to the world's first "smell-based biosensing device"—aka an artificial nose.
MIT researchers can now mass-produce the receptors humans use to detect odors. The finding has implications for law enforcement, medicine and the military.
Drug- and explosive-sniffing dogs could become obsolete, for example.
Certain cancers—lung, bladder, skin—that produce distinctive odors in their early stages could be identified using such a device, Shuguang Zhang, associate director of MIT's Center for Biomedical Engineering and senior author of the study, said in a statement.
The Defense Advanced Research Projects Agency (DARPA)—the research branch of the U.S. Department of Defense—has committed to funding a large collaborative project, dubbed RealNose, with Zhang at the helm.
(Related: "Robo-Nose: Hi-Tech Bomb Sniffer Smells Like a Dog" [October 1, 2003].)
Olfactory receptors, the proteins responsible for the sense of smell, are notoriously difficult to isolate in the lab.
Until now, researchers have had difficulty producing them in quantities large enough to be useful, as the proteins lose their structure when exposed to water.
The research team spent several years isolating and purifying receptor proteins using ingredients such as wheat germ and detergent. Now the scientists can grow large amounts, enough to use in research and industry.
Luca Turin penned the 2006 book The Secret of Scent: Adventures in Perfume and the Science of Smell and is a biophysicist at Flexitral, a Virginia scent and flavor lab. He called the study a "landmark piece of work."
"Shuguang's group has overcome great technical difficulties and is now in a position to produce milligram quantities of pure olfactory receptors," he said. "Once you can do that, all manner of avenues open.
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