A rapid CRISPR-based diagnostic tool for the detection of SARS-CoV-2 is reported in Nature Biotechnology. This diagnostic tool can return a result in about 45 minutes with comparable accuracy to that of conventional RT-PCR testing.
Previous large-scale epidemics have highlighted the need for rapid and accessible testing to enable an effective public health response. However, current tests for SARS-CoV-2 take several hours to several days to generate results .
Charles Chiu and colleagues report a CRISPR–Cas12-based test that can identify SARS-CoV-2 in RNA extracted from respiratory swabs of COVID-19 patients. The test, named SARS-CoV-2 DNA Endonuclease-Targeted CRISPR Trans Reporter (DETECTR), takes the sample RNA and reverse transcribes it into DNA. It is then multiplied by a technique called isothermal amplification. The SARS-CoV-2 envelope (E) and nucleocapsid (N) gene sequences can then be detected using CRISPR–Cas12, which cleaves off a reporter molecule that confirms the presence of the virus. The authors tested the system on clinical samples from 36 patients with COVID-19 and 42 with other respiratory illnesses. The test achieved a 95% positive predictive agreement and 100% negative predictive agreement when compared to the RT-PCR test used by the US Centers for Disease Control and Prevention.
Unlike the RT-PCR test, which can take several hours and requires special equipment and cycles of heating and cooling, DETECTR is carried out at two fixed temperatures and provides results on a visual readout strip, similar to the one in a home pregnancy test, in about 45 minutes.
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