US: Researchers discover bionic nose secrets

Engineers from the Massachusetts Institute of Technology (MIT) in the US have found a way to mass produce smell receptors that may lead the way to the creation of artificial bionic noses that can detect disease.

The university's RealNose project could spell the end to the use of sniffer dogs to detect explosives or poisons and could also be used to help diagnose disease by identifying an odour specific to a medical condition such as cancer or diabetes.

MIT researchers used a technique involving cell-free protein synthesis using commercially available wheat germ extract to produce a particular smell receptor, the nerve centre of biological noses. They then isolated the protein through several purification steps, enabling them to quickly produce large amounts for further studies.

Until now, researchers had trouble knowing how the sense of smell operates.

"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 utilise and should enable many new studies into smell research," said Brian Cook, a PhD student who based his thesis on this work.

Shuguang Zhang, associate director of MIT's center for biomedical engineering, said the team would work with international researchers to develop a portable microfluidic device that could identify an array of different odours. The device could be used for the early diagnosis of certain diseases that produce distinctive smells, such as diabetes and lung, bladder and skin cancers. There are also a wide range of industrial applications for such a smell-based bio-sensing device.

Humans have 388 different olfactory receptor genes that can help us identify many smells but mice and dogs have close to 1,000 olfactory receptor genes.

monica.dobie@uw-news.com