Many people are at least partially aware of paper-based diagnostic testing. The technique is most commonly associated with over-the-counter pregnancy tests. While the technique has been around for a while, researchers are now attempting to bring paper-based diagnostics to more complex medical testing. If successful, it could mean a dramatic reduction in medical costs and greatly improve accessibility in developing nations.
At the University of Washington in Seattle, a team of researchers has made a breakthrough that may open the doors to a wide variety of paper diagnostics. Their work deals with amplifying the signal of a test antibody by improving the timing of chemical delivery associated with the paper test. Success in this endeavor essentially amplifies the sensitivity of the test, allowing for indicators of a disease to be identified even at low levels.
Ultimately, the goal of the team is to replace complicated and expensive ELISA instrumentation. ELISA stands for enzyme-lined immonsorbent assay, a test that is currently used to detect proteins and antibodies linked to a variety of illnesses. While this current technology is highly accurate, it also requires large, expensive equipment that must be monitored by lab technicians. Switching over to paper-based diagnostics would put such tests into a credit-card sized piece of paper and eliminate the need for trained professionals.
With the amplification problem now solved, the team in Seattle is now working on packaging the technology so that it can be easily distributed.
In related news, a team of researchers at Australia’s Monash University has successfully created a paper diagnostic test for determining blood type. The simple dipstick test requires a drop of blood to be placed on a piece of paper that has been imprinted with antibodies. Depending on how the blood seeps into the paper, testers can quickly and easily determine if a patient’s blood type is A, B, AB or O.
Knowledge of blood type is integral for a number of reasons, including blood transfusion. The speed and affordability of the new test could greatly improve the success rate of such procedures in developing countries. According the team, the same basic technology may also be extended to blood tests that diagnose blood-related illnesses such as tuberculosis, anemia and diabetes.