DNA test on a fast track

Analysing DNA samples in criminal investigation takes almost a month. A new device quickens the process to an hour.

Researchers at suburban George Mason University have helped develop a small device that can quickly analyse DNA samples, potentially helping law enforcement agencies speed up criminal investigations.

The technology allows for a series of laboratory functions used to assess samples to be placed on a single microchip. Analysing DNA, the genetic instructions used in the development and functioning of all known living organisms, partially involves heating and cooling a section of the samples several times to read its code. The chip, placed into an instrument as small as a cellphone, uses microwaves to rapidly increase the sample8217;s temperature so that the sliver of DNA can be read properly.

Generally, the chips are millimeters to several square centimeters in size, university officials said.

Researchers said that eventually a tiny drop of blood or saliva gathered by police investigators could be placed in the instrument, with results available within an hour. The device would be hooked up to a laptop computer, where the results would be read. Currently, the DNA testing process takes months.

8220;When investigating a crime, time is of the essence,8221; said Rao Mulpuri, a professor of electrical and computer engineering at GMU. 8220;By enabling law enforcement personnel to receive DNA results while still at the crime scene, we are providing them an opportunity to identify and apprehend suspects much more quickly.8221;

Two graduate students worked with Mulpuri and the National Institute of Standards and Technology, an agency within the Department of Commerce, which provided the grant to develop the technology. The results were published in the Journal of Micromechanics and Microengineering in November.

8220;The idea here is that we would like to do the things we do in a chemical laboratory that involve beakers and test tubes 8230; and make them small,8221; said Michael Gaitan, a team leader for the Gaithersburg-based institute, referring to the laborious three-step process currently involved in DNA testing. 8220;In the same way that 8230; computer chips take electronic systems and miniaturise them, so we could take small computers and make them more portable.8221;

Story continues below this ad

Gaitan said that other methods of heating miniature spaces have been tried, including infrared light, but no one had tried to integrate a microwave device into this process. University researchers said it could be as long as 10 years before the technology is ready for commercial use. Siddarth Sundaresan, one of two graduate students who worked on the project, said that trials must still be done to ensure that the technology is as accurate as possible.

8220;This is something that we want to get one hundred percent right,8221; because a mistake could make an innocent person appear guilty, said Sundaresan, who works at GeneSiC Semiconductor, in Dulles.

Researchers who developed the technology said that the instrument could save local, state and federal agencies money over time, as investigations are accelerated.

Gaitan said that federal agencies such as the Department of Justice are looking closely at such technologies as a way of making investigations faster and more efficient. He and Sundaresan said that the 8220;lab-on-a-chip8221; devices could have numerous other uses, such as testing exhaust emissions and quickly reading other kinds of medical samples.
-Chris L. Jenkins The Washington Post