SARS-CoV-2 detection with CRISPR diagnostics

The novel coronavirus (CoV) disease termed COVID-19 (coronavirus disease-19) caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) 1 is causing a massive pandemic worldwide, threatening public health systems across the globe. During this ongoing COVID-19 outbreak, nucleic-acid detection has played an important role in early diagnosis 2 . To date, four protocols based on CRISPR for detecting SARS-CoV-2 have been published 3 , 4 , 5 , 6 . Using lateral flow protocols, RNA samples harboring more than 1 × 10 4 –1 × 10 5 copies/mL (SHERLOCK) or 1 × 10 4 copies/mL (DETECTR) can be detected within 1 hour. In addition to these reported efforts, we have also established a SARS-CoV-2 detection protocol based on our previously reported platform—CDetection (Cas12b-mediated DNA detection) 7 . By combining sample treatment protocols and nucleic-acid amplification methods with CDetection, we have established an integrated viral nucleic-acid detection platform—CASdetec (CRISPR-assisted detection). The detection limit of CASdetec for SARS-CoV-2 pseudovirus is 1 × 10 4 copies/mL, with no cross-reactivity observed. Here, we present our assay design and optimization process, which could provide guidance for future CRISPR-based nucleic-acid detection assay development and optimization.