In Harry Potter and the Chamber of Secrets, one of the most influential secrets of the entire Harry Potter series was seen in the form of Tom Riddle's Diary. A book that at first glanced appeared completely unmarked. However, communication to the viewer was readily apparent through ink that seemed to rise through the paper inside the book. This concept inspired Australian researchers to create a new blood test that would help eliminate incorrect blood types on individuals.
According to a new article, if the wrong blood type is used during a transfusion to a individual, death could occur, and rapid tests in the past are not completely uncomplicated and can lead to disaster. In the journal Angewandte Chemie, researchers explained a new "responsive" paper that indicates blood type as unambiguous text, almost as if Tom Riddle himself wrote the answer.
From the article:
Like the conventional laboratory technique, this test is based on the fact that red blood cells agglutinate or clump together when they encounter antibodies directed against their antigens. The paper is printed with a hydrophobic layer with four windows left “open”. These windows contain the antibodies. In the windows containing the antibodies that correspond to the sample, the red blood cells agglutinate to form large clumps and get caught by the paper fibers, leaving behind a red tint even after washing with saline solution.
So how does the paper “write” the blood type? For types A, B, and AB it is easy: Two of the windows are shaped like the letters A and B, and are filled with the antigens A and B, respectively. Type A results in a red tint in the A-shaped window, type B in the B-shaped window, and type AB in both. However, type O doesn’t respond to any antibody, so the researchers had to get creative. They made the third window in the shape of an X, included antibodies against A and B, and printed on a red letter “O”, which was printed with a waterproof ink. Blood types A, B, or AB turn the X red, telling the user that the sample is not O type by “crossing out” the O. If the sample is type O, the X becomes white after saline washing, leaving only the red letter O.
The researchers were equally clever in their approach to indicating whether the blood is RhD positive or negative: The fourth window is shaped like a vertical line and contains antibodies against rhesus factor D. A red horizontal line is printed on the paper with the water-proof ink. If the blood is RhD positive, it tints the vertical line red. In combination with the printed water-proof horizontal line, this forms a plus sign. If the blood is RhD negative, the vertical line becomes white after saline washing and the paper shows only a minus sign.
Once again, J.K. Rowling has inspired a solution in today's world, only this time the solution rose from within the pages of the book...literally!