Researchers in Australia say they've successfully engineered the first dipstick-like blood-type test. By placing a drop of blood on a thin piece of paper that has been specially printed with antibodies, the blood's type is revealed based on which parts of the paper it seeps into.
The team, led by chemical engineering professor Gil Garnier at Monash University in Victoria, estimates the cost of the test at 10 cents. (By comparison, simple blood-type tests typically cost at least $15.)
The main grouping of blood types is ABO, and results in type A, type B, type AB, or type O (O indicating zero or absence of antigens). A separate grouping system, Rh, essentially qualifies blood types as positive or negative. The vast majority of people, then, have a blood type that can be characterized as A positive or A negative, B positive or B negative, AB positive or AB negative, and O positive or O negative.
Knowing one's blood type is crucial in the event that a blood transfusion is necessary, as complications such as shock and renal failure can occur between certain incompatible blood types. Someone whose blood type is O negative is considered a universal donor, while someone who is AB positive is a universal recipient.
The engineers and material scientists had actually been experimenting with different substances when they noticed something strange. "When you put a drop of blood on a Kleenex, it goes everywhere," Garnier told MIT's Technology Review. "But if it agglutinates [thickens], it stays in one place."
So they built a piece of paper with three arms, each printed (using enzymes or antibodies instead of ink in a modified ink-jet printer) with a different antibody to match the antigens on red blood cells--one for A, one for B, one for Rh.… Read more