A prototype hydrogel wax chip and manufactured plastic chip for malaria diagnosis. (A) Core concept for hydrogel PCR. A single hydrogel strip (yellow) is desiccated and adheres to one surface of the chip creating a channel underneath for sample delivery. Blood flows through the channel by capillary force and is absorbed by the gel. (B) A wax chip with trenches overlaid with hydrogel bound to a glass coverslip. Blood is manually loaded into the channel below each hydrogel strip. (C) A plastic chip composed of top and bottom pieces of molded plastic. The gel is housed within a well in the top piece. In the current study, blood was added directly to the hydrogel in the open chip, and the two pieces of plastic were sealed prior to PCR. With this design, blood can also be added via the circular sample ports in the pre-sealed chip.