At-Home COVID Test

Scientists have developed a new coronavirus test that could be performed by patients at home and provide results within an hour. It can also determine with which variant a user is infected. The device – known as miSHERLOCK –uses CRISPR-based technology to find viral RNA in saliva samples. Although coronavirus testing typically uses nasal swabs, several studies have reportedly found that saliva tests achieved similar accuracy. In addition, the SARS-CoV-19 virus is detectable in saliva for a longer period after infection.

The battery-operated device, which can be produced on a 3D printer, contains two chambers. A heated preparation chamber preprocesses the saliva sample to disable enzymes (called salivary nucleases) that can destroy RNA. After three to six minutes, the saliva passes through a filter which the user then transfers to a reaction chamber. In less than an hour, a fluorescent signal will appear which can be analyzed with a smartphone app for a positive or negative diagnosis.

miSHERLOCK was tested on 27 infected patients and 21 healthy patients. It correctly identified positive patients 96% of the time and negative patients 95% of the time. It also effectively distinguished between alpha, beta, and gamma variants. At a cost of about $15, devices such as this could be extremely helpful in tracking the virus and its long-term effects.