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The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi. org/10.1101 org/10. /2020 The whole workflow of our study from in-silico analysis to analytical evaluation and clinical 143 validation is depicted in Figure 1 . Nine and six LAMP primer systems were designed and evaluated 144 in-silico, but only the six primers showed the highest sensitivity and specificity, which used in the 145 next steps (Table 1) . Primarily, our assay was meant to be quantitative and it showed an optimal 146 reproducibility when tested in analytical evaluation step using armored viral particle diluted in water 147 (R 2 value 0.99) and sputum sample (R 2 value 0.83). Analytical sensitivity yielded reliable LOD of 148 500 copies/ml less than 30 minutes regardless of matrix used for serial dilution (Figure 1 ). Of note, 149 our assay could detect 50 copies/ml, but some replicates showed unstable amplification. Therefore, 150