Development and validation of a rapid single-step reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) system potentially to be used for reliable and high-throughput screening of COVID-19

Minghua Jiang; Wenjie Fang; Amir Aratehfar; Xiaojing Li; Liyan ling; Hua Fang; Farnaz Farnaz Daneshnia; Jian Yu; Wanqing Liao; Hao Pei; Weihua Pan; Cornelia Lass-Florl

The virulent nature of this virus and its high rate of transmissibility warrants robust, rapid, sensitive, 51 specific, and quantitative diagnostic tools to supplement clinical symptoms aiding clinicians to 52 confidently rule in and rule out patients. Moreover, such a diagnostic tool will help with preventing 53 spread of virus by identifying the infected cases and can monitor the health status of infected patients 54 by quantifying the viral load. Center for Disease Control was the first to develop a quantitative 55 reverse transcriptase real-time PCR (RT-PCR), which later became the gold standard technique 56 (https://www.cdc.gov/coronavirus/2019-ncov/about/testing.html). Subsequently, a Chinese group 57 used a RNA-based metagenomics next generation sequencing (mNGS) to diagnose the viral RNA 58 from the clinical samples of two patients (3). However, the requirement for advanced technology and 59 skilled personnel and long turn-around time (24 hours) are not feasible for local and referral 60 laboratories. Therefore, a colorimetric loop mediated isothermal amplification, also known as LAMP, 61 was developed to obviate the need for expensive technologies, e.g. real-time PCR and NGS, as well 62 as to shorten the turn-around time to up to 40 minutes (4). However, this assay was a qualitative one 63 and also only the swab samples from limited number of patients (n=7) were included for testing (4). 64