Team Sniffs Out Process That Could Make 'Artificial Nose'

TUESDAY Sept. 30, 2008 -- Smell receptors can now be mass produced in the laboratory, an advance that the biological engineers who developed the process say could lead to the creation of "artificial noses," a new report says.

In a paper published in this week's issue of the Proceedings of the National Academy of Sciences, biological engineers from the Massachusetts Institute of Technology say they used cell-free synthesis on commercially available wheat germ extract to produce a particular receptor. Then, through several purification steps, they isolated the proteins that detect odors, known as olfactory receptors.

The technique can quickly produce large amounts of these proteins, which could be used to help scientists finally unlock the mystery of how the sense of smell works and recognizes so many different odors.

"The main barrier to studying smell is that we haven't been able to make enough receptors and purify them to homogeneity. Now, it's finally available as a raw material for people to utilize and should enable many new studies into smell research," Brian Cook, who just defended his MIT doctorate thesis based on this work, said in an MIT news release.

According to the MIT team, the creation of artificial noses eventually could replace drug- and explosive-sniffing dogs, and might have many medical uses.

Smell is one of the most complex and least understood senses. Humans have a vast olfactory system that includes close to 400 functional genes, more than are dedicated to any other function. That variety of receptors allows people to discern tens of thousands of distinct odors.

In the past, removing and isolating the key proteins from the cell for detailed study has proved difficult, said Liselotte Kaiser, lead author of the PNAS paper. The MIT team, after several years, finally hit on a way to isolate and purify the proteins in a multi-step process using a hydrophobic detergent solution that maintains the proteins' structure and function.

The team plans to work with other researchers worldwide to try to create a portable microfluidic device that can identify an array of different odors.

More information

The Howard Hughes Medical Institute has more about your sense of smell.

Posted: September 2008


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