THURSDAY, April 16, 2020 (HealthDay News) -- Researchers say they have developed a low-cost swab test that can diagnose coronavirus disease 2019 (COVID-19) infections in about 45 minutes.
The CRISPR-based test -- which uses gene-targeting technology and requires no specialized equipment -- could help relieve testing backlogs in the United States as COVID-19 continues to spread. The U.S. Food and Drug Administration has not approved the test, but clinical assessments are being conducted in an effort to fast-track approval. The test is described in a paper published online April 16 in Nature Biotechnology.
The new test -- dubbed SARS-CoV-2 DETECTR -- is among the first to use CRISPR gene-targeting technology to test for the presence of COVID-19. CRISPR can be modified to target any genetic sequence, so test developers "programmed" it to zero in on two sequences in the genome of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). One sequence is common to all SARS-like coronaviruses, while the other is unique to SARS-CoV-2. According to the researchers, checking for both sequences ensures that the new test can distinguish between SARS-CoV-2 and closely related viruses.
Like other tests, this one can detect COVID-19 in samples from respiratory swabs from patients. It provides results in about 45 minutes compared with roughly four hours for widely used tests based on polymerase chain reaction (PCR) techniques. The researchers say that another advantage of the new test is that it can be performed in virtually any lab using off-the-shelf chemical agents and common equipment. The new test is also easy to interpret. Much like a store-bought pregnancy test, dark lines appear on test strips to indicate the presence of COVID-19 genes. While the new test is slightly less sensitive than PCR-based tests, the researchers say that is unlikely to have much impact on diagnosis because infected patients typically have high viral loads.