DNA sensor changes color

University of Rochester researchers have designed a simple, inexpensive sensor that can detect specific sequences of DNA on-the-fly.

The researchers' sensor chip contains hairpin-like stalks of DNA that straighten to expose fluorescent molecules attached to their ends when they combine with a given sequence of DNA.

The chip could eventually be used as a cheap, instant test for biowarfare agents and pathogens like strep throat bacteria, and could also be used in genetic screening, drug discovery and forensics, according to the researchers.

The method is sensitive enough that it does not require the usual, time-consuming step of making thousands of copies of a piece of DNA in order to have enough material to test. To use the chip, a scientist would place a drop of solution containing the DNA to be identified onto the chip and watch for a change of color.

The researchers' prototype chip detects a type of staph bacteria. They are working on a microarray designed to detect several types of DNA at once.

It will take two to five years to perfect the technology for practical use, according to the researchers. The work appeared in the April 9, 2003 issue of the Journal of the American Chemical Society.