10 Cent Blood Type Test Could Save Lives
A new blood type test that costs less than 10 cents each and is highly portable could save lives around the world, according to its developers. The first dipstick-type blood test is the brainchild of researchers at Monash University in Australia, and requires just one drop of blood.
Current blood type tests costs hundreds of dollars per test and involve intricate analysis using optical or microfluidic devices. Knowledge of a person’s blood type is essential for blood transfusions, because if the wrong type of blood is given to an individual, the person may die. It is also critical for pregnant women to have their blood typed, and blood type tests are also done to determine whether two people are likely to be blood relatives.
Human blood is typed by looking for certain markers, called antigens, on the surface of red blood cells. There are four main blood types—A, B, AB, and O—and the two most common blood type tests are the ABO and Rh tests.
For the new test, researchers developed a strip of paper that has three arms, each one printed with a different antibody that matches the antigens on red blood cells. When a drop of blood is placed in the center of the bioactive strip, the blood disseminates along each arm. The blood agglutinates, or clumps and stops, when it meets a matching antibody, which then reveals the person’s blood type.
Gil Garnier, a professor of chemical engineering at Monash University who led the study, noted in Technology Review that the test has the same accuracy as currently available lab-based blood type tests. He believes that the bioactive paper used for the new blood type test could eventually be useful for other types of blood tests, such as those that detect anemia, diabetes, and tuberculosis.
Researchers are still working on perfecting the technique before the test is ready for action. One hurdle is making sure the paper can withstand high temperatures, as many of the climates where the test is needed are very hot. The test as it now stands also cannot test for everything, such as cross-matching to control against reactions from non-ABO, non-Rh antigen incompatibility.
A 10-cent blood type test may be just what the doctor ordered. According to the World Health Organization, about 120 countries identified a total of 51,400 hospitals that performed blood transfusions in 2007, serving approximately 3.6 billion people. Many of those served were in developing countries or in areas with meager funds. Garnier says that their portable paper blood type test could provide “low-cost and accessible information to empower people, especially in developing countries.”
Technology Review, June 9, 2010
World Health Organization