Researchers from Cornell University have developed a miniaturized DNA-based biological testing system that fits on a silicon chip and can be customized to detect a wide variety of microorganisms.

The 2 cm x 4 cm chip captures the DNA from the sample and purifies it. A reaction chamber performs a polymerase chain reaction to rapidly replicate the selected segment of DNA, which can then be tested.

Cady and his colleagues are currently working on incorporating a 3rd step to the process that uses fluorescence technology where an added dye would glow green to indicate a positive sample.

“Other people have developed real-time PCR on silicon chips, but nobody has really done the purification of the DNA sample on the same chip,” says Nathan Cady, one of the researchers on the study. “As near as we can tell, we are one of the first groups to incorporate the purification step into the chip.

“It simplifies the process. You can hand this to someone in the field, someone who is not a trained lab technician, and they can do it.”

Another advantage of this system is that it has a very broad range in what organisms it can be used to detect. That makes it very useful for a variety of purposes from monitoring food and water supplies to detecting agents of biological warfare.

American Society for Microbiology press release