CRISPR-Cas-based assays for the detection of SARS-CoV-2 RNA

The COVID-19 pandemic caused by the SARS-CoV-2 epidemic now requires the deployment of fast, sensitive and inexpensive diagnostic methods to facilitate disease management and containment worldwide. The real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay is currently the standard method for detecting SARS-CoV-2 virus. However, lack of access to laboratory resources (including rRT-PCR instrumentation, reagents, or even trained laboratory technicians) limits rRT-PCR assays from being a field-deployable and rapid diagnostic tool, especially in resource-constrained pandemic zones. Given this limitation and the necessity of expediting the diagnostic procedures, there is a strong need to develop an accurate point-of-care (POC) testing platform for COVID-19 with quick turnaround times. A POC community-level quick test (used as an initial screening test before subsequent confirmation by rRT-PCR in a central laboratory) can significantly improve diagnostic utility and ultimately reduce the burden on medical resources. CRISPR-Cas technology has now surfaced as a promising diagnostic tool with rewarding prospects of rapid detection and low cost, thereby serving as a POC one-stop platform to detect COVID 19 infection and loads. Herein, we review various hitherto CRISPR-Cas-based methodologies for the detection of SARS-CoV-2 viral RNA.