Single-copy sensitive, field-deployable, and simultaneous dual-gene detection of SARS-CoV-2 RNA via modified RT–RPA
Simin Xia, Xi Chen
Abstract
Since the end of 2019, the world is suffering an outbreak of COVID-19 pneumonia caused by SARS-CoV-2 (2019-nCoV) 1 with over 84,000 infections in China and over 3,000,000 infections outside China worldwide (as of April 28th, 2020). The whole genome of SARS-CoV-2 was sequenced and then released to the public on January 5th, 2020 2 , which served as the basis for nucleic acid-based diagnostics such as reverse transcription–polymerase chain reaction (RT–PCR) 3 , 4 . Since human-to-human transmission has been confirmed 5 , 6 , field-deployable detection methods against SARS-CoV-2 are highly required (Supplementary Fig. S1 ). In addition, detection sensitivity is important for early-stage diagnostics and to reduce false-negative results. While RT–PCR is widely used to detect viral RNA, it is not readily field-deployable because of the high cost of real-time PCR machine and the expertise required to perform the analysis. Antibody-based diagnostics are usually field-deployable, but it takes weeks or months to produce high-titer antibodies; additionally, they are usually not as sensitive and specific as nucleic acid-based approaches 7 . Gene editing has also recently been introduced for the detection of RNA, which requires multiple reaction steps 8 .