“A, B,AB or O: a paper-based test could reveal your blood type in just half a minute, allowing hospitals to rapidly administer the right blood in an emergency.” (New Scientist, 2017, p.19).
The test could be particularly useful in war zones or remote areas where there are no labs to carry out blood typing.
Knowing your blood type is essential if you ever need a transfusion, because a mismatch can send the immune system into meltdown. But conventional blood typing takes 10 to 20 minutes, so most emergency departments stock only a type of O blood. This is safer because it lacks the antigens that trigger immune reactions, but supplies are limited.
Now Hong Zhang at the Third Military Medical University in China and his colleagues have developed
a rapid test that anyone can perform at a patient’s bedside. Each low-cost paper strip is impregnated with a matrix of dyes and antibodies that recognise antigens on the surface of red blood cells. When blood is applied, squares of colour develop depending on which antigens are present, revealing the sample’s blood type.
In trials of 3550 human blood samples, the strip was more than 99.9% accurate, and only
took 30 seconds to produce results (Zhang et al., 2017).
New Scientist (2017) O My! Blood Typing in 30 Seconds. New Scientist. 25 March 2017.
Zhang, H., Qiu, X., Zou, Y., Ye, Y., Qi, C., Zou, L., Yang, X., Ynag, K., Zhu, Y., Yang, Y., Zhou, Y. & Luo, Y. (2017) A dye-assisted paper-based point-of-care assay for fast and reliable blood grouping. Science Translational Medicine. 9(381), eaaf9209. DOI: 10.1126/scitranslmed.aaf9209.