Cheap Blood Typing
A 10-cent paper test could improve medical care in poor countries
Source: “Paper diagnostic for instantaneous blood typing”
Gil Garnier et al.
Analytical Chemistry 82(10): 4158-4164
Results: Researchers made a blood-typing test from a piece of paper treated with antibodies. It can determine an individual’s blood type as accurately as more complex existing methods.
Why it matters: Blood transfusions can cause a potentially fatal reaction if the recipient’s and donor’s blood types conflict. Current methods of determining blood type require costly machinery, which is often difficult to obtain or maintain in poor countries. The new test costs about 10 cents to make.
Methods: Using an ink-jet printer, researchers printed a pattern of channels on paper with hydrophobic ink. Then they used the printer to deposit antibodies designed to bind to specific molecules associated with the different blood types. On each of three tabs extending from the center of a piece of paper, they printed a different antibody within the channels. Blood dropped into the center diffuses along the tabs and stops when it encounters the antibody that matches the molecule characteristic of its type. Scientists read the results by assessing how far the blood has traveled down the tabs.
Next steps: The researchers are now looking for industrial partners to bring the diagnostic to market.