In the book “Harry Potter and the Chamber of Secrets” by J. K. Rowling, Harry writes a question in Tom Riddle’s diary—and a written answer appears.
Australian researchers were inspired by the idea of paper that writes on itself. In the journal Angewandte Chemie, they have introduced a blood test that indicates blood type in plain text.
Rapid tests made of paper are a simple and inexpensive alternative for diagnostic tests, particularly for use in developing nations. However, they are not completely uncomplicated, and a lack of expertise can lead to fatal misinterpretations. For example, if the wrong supply is used for a blood transfusion, it could result in death. A team led by Wei Shen at Monash University has now developed a “responsive” paper that indicates blood type as unambiguous text.
Currently, blood types are classified with the ABO system, in which designations of A, B, AB, and O are possible.
The letter indicates which antigens are present on the red blood cells. Individuals with type A blood have type A antigens, those with type B have type B antigens; individuals with blood type AB have both types of antigens, those in the O group have no antigens. The system is also used to indicate whether the blood cells have rhesus factor D (RhD positive) or not (RhD negative).
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.About the Author
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201201822
Wei Shen | Angewandte Chemie
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy