I don't know if y'all have heard about it, but there is a nasty virus going around right now. This virus, called SARS-CoV-2, can cause serious symptoms and even death. It is also quite contagious, which has forced some states and countries to implement lockdowns and other safety measures. If you're experiencing flu-like symptoms, you should get tested. But the typical test, which requires a nasal cavity swab, is very unpleasant. That's why a team of researchers from the Wyss Institute at Harvard University and MIT built this affordable device that can taste COVID-19 variants in your saliva.
This device, dubbed miSHERLOCK, makes COVID-19 testing a snap. Just swap spit with the device, wait a little less than an hour, and you get a notification on your phone telling you your results! It can distinguish between three different SARS-CoV-2 and quick reconfigurations allow it to detect new strains, like the Delta variant that you've been hearing about lately. Best of all, the device is cheap to build. It only requires about $15 worth of off-the-shelf electronic components and some 3D-printed parts. Some of the hardware has to be replaced between tests, but individual assays cost about $6 each.
This testing procedure relies on CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology, which allows for gene editing. The team used that for SHERLOCK (Specific High Sensitivity Enzymatic Reporter Unlocking), which let them create special "molecular scissors" that can cut a unique gene out of SARS-CoV-2 RNA at. That gene, called Nucleoprotein, is present in multiple variants of the virus. A similar process can isolate other protein sequences representative of different variants. Combined with single-stranded DNA probes, they produce a detectable fluorescent glow.
The real appeal of this device is how it simplifies testing. It automatically handles several cumbersome steps, including mixing chemicals to prepare the saliva, heating the sample, and mixing the molecular scissors. In about 55 minutes, the samples will produce a fluorescent signal if SARS-CoV-2 is present. A special smartphone app looks at the samples through the camera and analyzes the image to avoid false positives or negatives. The team behind miSHERLOCK, hopes to make it commercially available soon.