Amplification-free detection of SARS-CoV-2 with CRISPR-Cas13a and mobile phone microscopy

By P. Fozouni, S. Son, M. Díaz de León Derby, Gavin J Knott, C. N. Gray, Michael V D'Ambrosio, Chunyu Zhao, N. Switz, G. R. Kumar, S. I. Stephens and 22 more. Cell, 2020

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SUMMARY The December 2019 outbreak of a novel respiratory virus, SARS-CoV-2, has become an ongoing global pandemic due in part to the challenge of identifying symptomatic, asymptomatic and pre-symptomatic carriers of the virus. CRISPR diagnostics can augment gold-standard PCR-based testing if they can be made rapid, portable and accurate. Here we report the development of an amplification-free CRISPR-Cas13a assay for direct detection of SARS-CoV-2 from nasal swab RNA that can be read with a mobile phone microscope. The assay achieved ~100 copies/μL sensitivity in under 30 minutes of measurement time and accurately detected pre-extracted RNA from a set of positive clinical samples in under 5 minutes. We combined crRNAs targeting SARS-CoV-2 RNA to improve sensitivity and specificity, and directly quantified viral load using enzyme kinetics. Integrated with a reader device based on a mobile phone, this assay has the potential to enable rapid, low-cost, point-of-care screening for SARS-CoV-2.

Subfields: Biomedical Engineering, Infectious Diseases, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/b098dc6d2b5c77fa284d2c1ee767b860427072b2