TROOPS on the battlefield could soon get early warning of a bioweapons attack from a chip that鈥檚 already at the heart of every mobile phone. So promising is the concept that the US Army is now financing research to develop a practical device.
Lydia Sohn and her colleagues at Princeton University in New Jersey have been able to identify proteins in cells by detecting the characteristic microwaves they emit when they vibrate. This should give a more accurate picture of living cells, unlike the conventional method of analysing their contents by splitting them open.
In Sohn鈥檚 device, the cells float down a microchannel etched in glass past a receiver sensitive to microwaves with a frequency of several gigahertz, just like the chips that pick up the signal in a mobile phone.
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Although the microwave signals from proteins are far fainter than mobile-phone signals, Sohn found that the latest receiver chips could still pick them out. The researchers tested the concept with E. coli cells that had been genetically modified to overexpress a fluorescent yellow protein.
鈥淲e definitely picked it up,鈥� says Sohn. She hopes the device will also make it easier to identify cancer cells in biopsies, or pathogenic bacterial cells that have a particular protein associated with them.
Although most proteins emit some kind of microwave, Sohn says the more proteins she tries to identify, the harder it becomes to unravel the different signals. 鈥淭here鈥檚 a complex network of proteins in a cell,鈥� she says. 鈥淚 don鈥檛 know if we can identify more than two simultaneously.鈥�