Infectious diseases can spread very rapidly, so quickly identifying them can be crucial to stopping an epidemic. However, current testing for such diseases can take hours and days. But not for much longer. Jayne Wu and Shigetoshi Eda, both at the University of Tennessee, have developed a portable device that can be used onsite to detect infectious diseases and pathogens in people and animals. To test for disease, a droplet of blood is placed on a microchip within the device. The microchip is treated with disease-specific antigens -- a toxin or other foreign substance that induces an immune response in the body -- and captures disease-specific antibodies in the blood. If the antigens and antibodies match, then the device tells the health care provider that the patient or animal is infected. This happens in a matter of minutes. So far the device has been used to detect tuberculosis in humans and wild animals, as well as Johne's disease in cattle.