From Monash magazine, October 2014:
Giving someone the wrong blood in a transfusion causes the body to go into anaphylactic shock as the immune system is effectively forced to attack itself. Determining a patient’s blood type traditionally requires complex and expensive laboratory equipment, careful refrigeration of antibody reagents and a university degree in pathology. It is a test that must be 100 per cent accurate: a mistake can be fatal.
But inspired by the magical Harry Potter diary that absorbs ink and prints its own letters, Monash University researchers Professor Wei Shen and Professor Gil Garnier have invented a paper-based test that spells out the correct blood type … in blood.
Their innovation, which could be a significant boost to medical care in poorer and more remote regions of the world, uses a piece of bioactive paper. The paper can be stored in a variety of conditions, maintains its efficacy for months, can be manufactured easily and cheaply, and can be used by almost anyone.
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. 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,” says Professor Garnier, a chemical engineer at Monash and director of the Australian Pulp and Paper Institute.
The result can then be easily interpreted according to which letter or letters remain highlighted in red. This seemingly magical technology comes down to relatively simple science that uses the porous structure of the paper, says Professor Shen, also a chemical engineer at Monash. Read more.