WIKIMEDIA, MARGRETTE DOMWhile existing tests can take anywhere from 5 to 20 minutes and require two steps to complete, a new paper-based diagnostic method, described in a paper published yesterday (March 15) in Science Translational Medicine, takes just 30 seconds to reveal whether a person is type A, B, or O, and a total of two minutes to reveal a whether the person is “positive” or “negative” for Rh factor, all with just one step.
Traditionally, blood typing requires forward typing, in which antibodies found in type A and type B blood are added to a blood sample to test for reactivity, followed by reverse typing, in which serum (cell-free blood) is mixed with the blood type identified in the first test. This stepwise process requires the separation of the serum using a filter—a procedure best carried out in a laboratory setting—and because the steps must be conducted consecutively, the whole process can take up to 20 minutes.
The new test, on the other hand, uses a paper strip that is coated in antibodies that recognize antigens found in different blood types, plus a commonly used green dye. When a drop of blood is put on the strip, it is ...
