Smartphones can now be used as laboratory-grade medical testing devices thanks to new kit designed by the University of Illinois. The transmission-reflectance-intensity (TRI) analyzer attaches to a smartphone to examine blood, urine or saliva samples as reliably as large, expensive equipment, but costs just $550.

The technology uses a high-performance spectrometer. First, a fluid sample is illuminated by the phone's internal white LED flash, then the light is collected in an optical fiber. The light is then guided through a diffraction grating into the phone's rear-facing camera, and a reading is provided on-screen.