Saliva Test Image
The SLIDE device analyzes saliva and could help make COVID-19 testing quicker and easier. (Credit: Weihua Guan)

A fast and sensitive COVID-19 test requires only a saliva sample; a palm-sized, portable device; and a smartphone.

The researchers integrated several steps into one compact machine, which they call the saliva-based SARS-CoV-2 self-testing with RT-LAMP in a mobile device (SLIDE). Its five distinct modules conduct all of the steps needed for RT-LAMP: heating the sample, mixing it with RT-LAMP reagents, carrying out the reaction, detecting how much viral RNA is present and communicating that result to a smartphone.

To use SLIDE, a person simply spits into a vial on a cartridge that they insert into the device, and results are sent to a smartphone within 45 minutes. In lab tests, SLIDE successfully detected and quantitated a mock saliva sample spiked with inactivated SARS-CoV-2 virus particles, as well as a real saliva sample from someone known to be positive for COVID-19. In both cases, the results were consistent with those from RT-PCR, which suggests that the SLIDE device could be a quick, easy, and sensitive way to tell whether someone has COVID-19, say the researchers.