MISSISSAUGA, Ont., April 30 -- Scientists at the University of Toronto have developed a new biosensor to screen for life-threatening fungal and bacterial infections, as well as diseases such as hepatitis or AIDS. The sensor is a DNA hybridization detection system that combines the precision of DNA chemistry with the speed of fiber optics to perform on-the-spot testing for organic molecules. Biosensors like the new system use actual organic molecules to detect reactions and convert them quickly to a recognizable signal. Professor Ulrich Krull, associate dean of sciences at the University, developed the sensor by attaching DNA strands directly to a fiber optic surface. The sensor looks for a specific DNA or RNA sequence; when the strands bind to the sequence in question, the resulting chemical changes are detected via the optical fiber. Unlike existing test procedures, the new system was designed to provide results in a matter of seconds.The new sensor has been successful in lab tests involving rapid screening for genetic material associated with fast-moving fungal infections, which often kill patients with weakened immune systems. Krull believes that technology similar to that used in the sensor could one day make testing for strep infections, hepatitis or AIDS as easy as using today's home pregnancy test. The hybridization detection system is currently in development at FONA Technologies in Mississauga, Ontario.