Lab on a Chip
It may soon be possible to diagnose many viral and bacterial infections on the spot using a portable device that reads blood or saliva samples.
Imagine being able to test for an infection in less time than it takes to get a prescription filled. A working model of a portable device that can do this has already been built, and the builders expect to have the real thing on the market by late 2010.
This unnamed device has been developed by a company associated with the University of Twente, in the Netherlands. The main part of the device is a chip which contains several channels. Each channel contains an immobilized antibody specific to a particular disease causing organism (usually a virus or bacterium). A blood or saliva sample taken from a person is diluted and allowed to flow into all the chip's channels. A sample from an infected person will bind to the antibody specific for that person's disease.
The other part of the device is a portable detector. This shoots a beam of light into the channels. If a person's sample has bound to an antibody on the chip, a change occurs to the light passing through the channel (to its interference pattern). This change is captured by the detector and shows that the person being tested is infected. The whole test can be completed in a few minutes.
The number of diseases or types of infection that be checked for in a single test is limited only by the number of different antibodies that can be placed on the chip.
The device is sensitive enough to detect how many disease organisms there are in a sample. This means it can not only detect an infection, it may also be able to tell how serious it is. Or detect an infection before any symptoms of it are present. The technique could also be used to detect the level of a protein such as PSA, which rises in men who have prostate cancer.
The speed, portability and the device's ease of use by relatively untrained personnel are major advantages over current lab tests. The portability eliminates the need for a laboratory. This should be extremely helpful to physicians, hospitals and public health officials.
This device would not be able to test for a new or unknown disease, because antibody specific to such a disease must first be available to put on the chip. It also couldn't test for a disease that may possibly be caused by an unknown virus, such as chronic fatigue syndrome, unless purified antibody exists. But these limitations pale before the device's possibilities.
At present the device is supposed to debut in late 2010. Dr. Aurel Ymeti first successfully demonstrated the technology in 2007 while he was a doctoral student at the University of Twente. Dr. Ymeti has also been involved in the refinements made to the device since then.