Researchers at a university in Australia recently invented a paper-based test that identifies the correct blood type—in blood, which could be very helpful for medical care in poor and remote parts of the world. The test uses bioactive paper, which can be stored in a variety of conditions, keep its efficacy for months, and made inexpensively and easily.

“The test works by having text and symbols to represent A, B and O blood types as well as Rhesus factor printed on the paper using special inks laden with the relevant antibodies for each blood type,” according to an article from Monash Magazine, which is published by Monash University. “A drop of blood is placed on each symbol, and the paper is washed with a saline solution. If the blood type is A, for example, it will interact with the antibody printed in that letter, causing it to coagulate and give an unambiguous report of the blood type.” 

“If this blood is specific to that antibody then the drop stays where it is and if it’s not specific, it will wash away,” Gil Garnier, a chemical engineer and professor at Monash University and director of the Australian Pulp and Paper Institute, said in the magazine article. Next, the result can be interpreted using the letters that are highlighted in red.

“When blood cells coagulate, their size increases and they get locked into the fibre structure, whereas in a negative test the cells can be flushed away by a saline solution,” Wei Shen, also a Monash University researcher, told the magazine.

Read the Monash University article to learn more about how this test works.