Researchers build device that can detect Covid-19 from saliva sample

A team of researchers has designed a small tabletop device that can detect SARS-CoV-2 from a saliva sample in about an hour.

In a new study, published in the journal Science Advances, the researchers, including James Collins from the Massachusetts Institute of Technology (MIT), showed that the diagnostic is just as accurate as the PCR tests now used.

"We demonstrated that our platform can be programmed to detect new variants that emerge, and that we could repurpose it quite quickly," Collins said.

"In this study, we targeted the UK, South Africa, and Brazilian variants, but you could readily adapt the diagnostic platform to address the Delta variant and other ones that are emerging," Collins added.

The device can also be used to detect specific viral mutations linked to some of the SARS-CoV-2 variants that are now circulating.

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This result can also be obtained within an hour, potentially making it much easier to track different variants of the virus, especially in regions that don't have access to genetic sequencing facilities.

The new diagnostic, which relies on CRISPR technology, can be assembled for about $15, but those costs could come down significantly if the devices were produced at a large scale, the researchers said.

For the study, the researchers first tested their device with human saliva spiked with synthetic SARS-CoV-2 RNA sequences and then with about 50 samples from patients who had tested positive for the virus.

They found that the device was just as accurate as the gold standard PCR tests now used, which require nasal swabs and take more time and significantly more hardware and sample handling to yield results.

The device produces a fluorescent readout that can be seen with the naked eye, and the researchers also designed a smartphone app that can read the results and send them to public health departments for easier tracking.