A new HIV test the size of a credit card promises to diagnose the disease in minutes rather than weeks, and could be deployed in sub-Saharan Africa as early as next year. In tests, it has detected the amount of CD4 cells in the blood in as little as 10 minutes. The CD4 count indicates the stage of HIV in a patient, and helps doctors determine the best treatment and how much of it to administer. The new test works by dropping a patient's blood sample onto a plastic biochip, which detects elements in the blood, says John McDevitt, the University of Texas chemist who helped develop the technology. The card is then inserted into a toaster-size analyzer, which determines the CD4 cell count.
"We etch silicon chips in ways that are very similar to what are used to make Pentium and other computer chips," McDevitt says. "But instead of transistors, we create little test tubes -- these little test tubes are miniature reaction vessels that hold artificial taste buds."
Austin biotech startup LabNow has licensed the technology and is developing it into a system that could be used to diagnose HIV quickly and cheaply. And HIV is likely only the beginning for McDevitt's technology. It can be reprogrammed, he says, to serve numerous application areas by simply changing the system's molecular-level code. He is developing systems for heart disease, cancer and infectious diseases, as well as bioterrorism-screening tools and environmental-monitoring aids.
"It is a lot like putting new software into a computer each time you want to work a new application area," he says. "You need not purchase a new computer; you simply use the existing infrastructure."
McDevitt is working with the Department of Defense to develop detectors that can "sniff" the air for anthrax spores and other bioterrorism agents.