Rapid Detection of Novel Coronavirus (COVID-19) by Reverse Transcription-Loop-Mediated Isothermal Amplification

Laura E Lamb; Sarah N Bartolone; Elijah Ward; Michael B Chancellor

The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.02.19.20025155 doi: medRxiv preprint Primers were designed for a conserved span of COVID-19 sequence that was found in 22 isolated COVID-19 strains but was a sequence that was also divergent from related coronavirus SARS. Given that all the isolated strains of COVID-19 thus far have shown very little genetic differences, we anticipate that this RT-LAMP will detect COVID-19 with the same level of confidence as qRT-PCR. This COVID-19 RT-LAMP assay was highly specific as it did not give a positive result for MERS, BtCoV, and MHV and had significant mismatch with numerous strains of SARS and common cold associated human coronoavirus strains 229E, NL63, HKU1, or OC43. We tested a range of temperatures from 57°C to 65°C; all the temperatures gave comparable results, indicating that this RT-LAMP reaction has a large temperature range with an optimal temperate of 63 ° C . We also tested a range of incubation times from 15-45 minutes. The optimal time for detection of RT-LAMP products was 30 minutes, however COVID-19 RT-LAMP products were detectable by UV light excitation or banding patterns on gels in as little as 15 minutes.