New at-home test detects COVID-19 variants in your spit

With the delta variant wreaking havoc on unvaccinated populations, the ability to quickly diagnose and track emerging variants of the virus is crucial. Researchers have now created a simple, inexpensive, CRISPR-based diagnostic test that allows users to test themselves for multiple variants of the SARS-CoV-2 virus at home, using just a sample of their saliva.

Developed by researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University, the Massachusetts Institute of Technology, and several Boston-area hospitals, the diagnostic device, called Minimally Instrumented SHERLOCK (miSHERLOCK), is easy to use and provides results that can be read and verified by an accompanying smartphone app within one hour.

miSHERLOCK successfully distinguished between three different variants of SARS-CoV-2 in experiments, and can be rapidly reconfigured to detect additional variants like delta. The device can be assembled using a 3D printer and commonly available components for about $15, and re-using the hardware brings the cost of individual assays down to $6 each.

“miSHERLOCK eliminates the need to transport patient samples to a centralized testing location and greatly simplifies the sample preparation steps, giving patients and doctors a faster, more accurate picture of individual and community health, which is critical during an evolving pandemic,” said co-first author Helena de Puig, a postdoctoral fellow at the Wyss Institute and MIT.

The diagnostic device is described in a paper published Friday in Science Advances.

From supply chain to SHERLOCK

As an instructor in pediatrics at Boston Children’s Hospital with a specialization in infectious diseases, co-first author Rose Lee has been working on the front lines of the COVID-19 pandemic for over a year. Her experiences in the clinic provided inspiration for the project that would ultimately become miSHERLOCK.