Detecting the virus that causes foot-and-mouth disease typically requires hours and a trip to the lab-hardly feasible when testing millions of animals or travelers' shoes. Now engineers at MIT's Lincoln Laboratory are developing a portable sensor to spot the virus in seconds.

The core of the sensor, dubbed Canary, is a dime-sized glass chip that can detect tiny amounts of the virus from a raw sample of blood, saliva or even air, says inventor Todd Rider. Rider says it is the first pathogen detector to use white blood cells, which are naturally sensitive to viruses and bacteria. The researchers inserted two genes into white blood cells from mice. The first gene produces an antibody on the cell's surface that binds only to the foot-and-mouth virus. When that binding occurs, a second inserted jellyfish gene makes the cells glow.

When the Lincoln Laboratory group tested Canary's speed against a U.S. strain of the foot-and-mouth virus, the sensor produced results in 25 seconds. Now, the researchers are genetically engineering cells to detect the European strain, a project they expect to complete by early summer. The U.S. Department of Agriculture is exploring the idea of using the device at airports and border stations.

Researchers have also engineered the device to detect several potential biological warfare agents; in theory, says Rider, it could be designed to sense any live pathogen. "You could walk into the doctor's office, cough on something and get an instant diagnosis."