Multistep Diagnostics on Paper
Paper-based diagnostic tests  represent an exciting opportunity for improving medical testing in poor countries. They are cheap to produce and don't require complicated instruments to carry out a test or read the result, so they can be implemented in areas with few resources and little infrastructure. But paper diagnostic tests have thus far been limited to fairly simple reactions. Researchers at University of Washington in Seattle have now taken an important step toward enabling more complex chemical reactions on paper.