It's In a Paper
Testing blood type made easier
(Ref:M S Khan et al, Anal. Chem., 2010, 82, 4158-4164) Schematic of colorimetric indication of phase separation on the paper channels
It would be, rather, a rare instance to find people not knowing their height or weight; but not knowing the blood type is a common phenomenon. Be it for the health insurance card or the driver's license, many a times we fail to provide our blood type either because we forgot the type or we never knew it. Blood typing is one of the most vital medical tests, yet many of us are unaware of our blood type and ignorant of the dire consequences this could lead to. Conventional blood typing methods are time-consuming, not on-the-spot and require the use of sophisticated instruments that are unavailable in many less developed countries. In scenarios, like a blood transfusion or an organ transplant, where knowing the blood becomes extremely crucial, an instantaneous test is certainly a remedy. At Monash University, Australia, Dr. Mohidus Khan*, a young Bangladeshi researcher, and his team developed the first ever paper diagnostics to determine blood type, that costs only a few cents and is as simple as placing a droplet of blood onto the paper strip, revealing the blood type in a minute or two. Blood Properties: Based on antigens, namely A, B and D present on the surface of red blood cells (RBCs), people have the following blood types: A (+/-), B (+/-), AB (+/-), and O (+/-). When these antigens interact selectively with their counter antibodies, A, B and D, e.g., antigen A interacting with antibody A, agglutination or clumping occurs. This increases the viscosity and consequently the blood flow (Ref :M S Khan et al, Anal. Chem., 2010, 82, 4158-4164). Based on these properties, a paper based blood typing test has been developed, where an antigen recognition agent in the paper structure specifically binds to antigens, resulting in a Mechanism of Blood Typing: The paper diagnostic is a three arms prototype (Figure1). Each arm is treated by printing different biological substances using a modified ink-jet printer, in which the ink is replaced by a solution of antibodies. When a drop of blood is placed in the center of the paper, it moves along each arm. When the specific antibody is met with and adsorbed on the surface of the antigen, the blood agglutinates and forms clumps of antigen-antibody complex, resulting in chromatographic separation of the RBCs from the plasma and revealing the blood type (Ref :M S Khan et al, Anal. Chem., 2010, 82, 4158-4164). "From Monash University, we have patented the concept of blood typing using paper diagnostics and are currently working with industrial partners for further development of the technique. We believe this work will open a new horizon to the researchers and will lead to the development of different pathological tests, yet restricted in well equipped pathological labs, using the much convenient paper diagnostics", says Dr. Khan. Paper based diagnoses, in the form of diabetes or pregnancy tests are prevalent for years. Compared to the conventional blood typing device available, the new technology of paper based analysis for instantaneous blood typing is cheap, biodegradable and most importantly a means by which patients, in both developed and developing countries can get the right treatment, faster. Dr. Mohidus Khan is now working as a post-doctoral fellow at the Department of Chemistry, McGill University, Canada.
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