UK team develops Trek 'tricorder'

A real-life version of Star Trek medic Dr McCoy's diagnostic marvel, the tricorder, is being developed by British scientists using viruses that behave like spaghetti.

The shoe box-sized prototype can already detect dangerous E.coli bugs in a sample in five minutes.

Future devices will identify a whole range of infections at the same time, and may be small enough to attach to a smart phone. A spin-out company to develop the technology, Linear Diagnostics, has been set up by the team at the University of Birmingham's School of Biosciences.

In the original Star Trek series, Dr Leonard "Bones" McCoy was hardly ever without his trusty tricorder. Diagnosing illness in a Starship Enterprise crew member was as simple as waving the device over the patient.

The tricorder has caught the public imagination to the extent that a 10 million dollar (£6.16 million) prize is waiting to be claimed by anyone who can build one, or something like it.

Dr Tim Dafforn, who heads the Birmingham bioscientists, thinks he could be in with a chance, telling journalists at a press briefing in London: "We'll be vying for that, absolutely."

The device is an example of new applications coming out of the emerging field of "synthetic biology", which involves re-engineering biological systems. At its heart are bacteriophages - viruses that attack bacteria. By attaching antibodies to the viruses, they can be made to "stick" to specific micro-organisms.

A "spaghetti-like" property of the long, thin phages allows them to be used as a detection system. Like strands of pasta, the viruses "line up" when stirred in a solution. But just as meatballs disturb rows of perfectly aligned spaghetti, bacteria cause the viruses to separate and tangle.

Polarised light shone through the viruses makes it possible to show when the bugs are present. The light is blocked by aligned viruses, but passes through them when they become tangled. This generates an electrical signal displayed as a set of numbers on a computer screen. So far Dr Dafforn has concentrated on detecting Escherichia coli (E.coli) O157, a strain of the stomach bug that causes serious infections.

"Current detection methods go back to Louis Pasteur, growing things on agar plates that take 10 to 14 hours," he said. "Our system can detect a pathogen in five minutes. It hunts down E.coli O571 in a sample and then uses it's noodle-like structure as a detection method. You stir noodles in a pan and they all align. This does the same thing."