World’s Smallest Microwave Oven Will Dramatically Increase Speed of DNA Testing

Posted: December 13, 2007 at 1:00 am, Last Updated: November 30, -0001 at 12:00 am

By Jennifer Edgerly

Researchers in the Volgenau School of Information Technology and Engineering and the National Institute of Standards and Technology (NIST) have created an instrument that will change the speed and format in which DNA samples are analyzed and results are returned.

The instrument, the world’s smallest known microwave oven, is intended for use as part of lab-on-a-chip devices, which integrate multiple laboratory functions on a single piece of equipment that is only millimeters to a few square centimeters in size.

Currently when analyzing DNA (known as DNA fingerprinting), samples must be sent to a lab. Getting results can take months. However, with the use of this new technology and lab-on-a-chip devices, results from DNA fingerprinting will be available in less than one hour. Although lab-on-a-chip devices are not currently available, researchers at Mason and NIST predict they will be available and widely used in the next five to 10 years.

“When investigating a crime, time is of the essence, and 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,” says Rao Mulpuri, professor of electrical and computer engineering at Mason.

“The lab-on-a-chip device will be able to connect directly to a laptop computer or other handheld electronic equipment, providing the ability to immediately compare the DNA results with libraries of DNA samples from known criminals.”

The miniature microwave oven needs only a tiny amount of DNA for analysis and is more energy efficient, costs less and produces results faster than current methodologies.

“In order to gain information about DNA, it has to be run through an amplification process,” says Siddarth Sundaresan, research associate at Mason. “What we have created is a way to cycle a small sample of DNA — the size of a pinhead — through a heating process without heating surrounding areas that may not be able to withstand the high temperatures that are needed.”

The miniature microwave oven created by Mason researchers has a height of 7 micrometers (the diameter of a red blood cell), a width of 25-50 micrometers and a length of nearly 4 millimeters (approximately the length of an ant). It can analyze fluid volumes ranging from a few microliters (millionth of a liter) to sub-nanoliters (less than a billionth of a liter).

Presently the miniature microwave only works with specimens that contain some water, such as blood, saliva and semen. In its current form it cannot analyze solid samples of DNA, such as hair.

The research is supported by the Office of Science and Technology at the Department of Justice’s National Institute of Justice.

Write to at