Fig 1. The KS-Detect system.

(A) The system contains all components necessary for solar thermal PCR and subsequent analysis, including reagents, tablet, and solar panel. The focusing lens is fixed to the red container on a hinge, allowing rotation (blue arrow) for alignment with the sun. (B) The system is easily carried in one hand, affording easy transportation to patients in remote communities. (C) Microfluidics schematic. Samples are cycled between the warmer center of a PDMS chip (for denaturation of DNA) and the cooler edges (for annealing of primers). A thin, black PDMS layer (not pictured) serves as the bottom of the microfluidic chip, and absorbs solar radiation. (D) Our custom Android application is used to track each temperature zone within the microfluidics and to (E) analyze results via fluorescence levels imaged by a smartphone or tablet.