Coronavirus: CRISPR-based test gives quick results

April 22, 2020

The test can diagnose infection in less than an hour.

A new CRISPR-based COVID-19 test can give results in less than an hour, a big step toward the widescale test and trace effort that experts say will be key in reopening the U.S., according to a news release.

The release says the new test, officially named the SARS-CoV-2 DETECTR, was developed at UC San Francisco and Mammoth Biosciences. It is easy to implement and to interpret, requiring no specialized equipment.

The test is still awaiting formal approval from the FDA, but researchers are clinically validating it in an effort to fast track its approval through an Emergency Use Action, the release says.

“The introduction and availability of CRISPR technology will accelerate deployment of the next generation of tests to diagnose COVID-19 infection,” the release quotes Charles Chiu, MD, PhD, professor of laboratory medicine at UCSF and co-lead developer of the new test, as saying.

The new test is one of the first to use CRISPR gene-targeting technology to test for the presence of the coronavirus. It uses the ability for CRISPR to be modified to target any genetic sequence to home in on two target regions in the genome of the coronavirus: one common to all SARS-like coronaviruses and one unique to COVID-19. By testing for both sequences, the new test can distinguish between SARS-CoV-2 and related viruses, the release says.

The test can be performed in virtually any laboratory, using off-the-shelf reagents and common equipment. It is also easy to interpret with dark lines appearing on test strips indicating the presence of viral genes, the release says.

It is also highly sensitive, being able to detect the presence of as few as 10 coronaviruses in a microliter of fluid taken from a patient. While the test is less sensitive than existing PCR-based tests, it is unlikely to have a noticeable impact on diagnosis due to infected patients having much higher viral loads, the release says.

Testing for COVID-19 has been a consistent thorn in the side of the Trump administration, as the U.S.’s slow start and continued failure to expand to scale has been seen by experts as a major roadblock in President Donald J. Trump’s efforts to ease social distancing guidelines that have seen the economy collapse. The lack of readily available testing has led the leaders of some states, particularly Massachusetts, seek tests from countries like South Korea, according to The New York Times