Colorimetric Reverse Transcription-Loop-Mediated Isothermal Amplification Assay for Rapid Detection of SARS-CoV-2

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been spreading rapidly all over the world. In the absence of effective treatments or a vaccine, there is an urgent need to develop a more rapid and simple detection technology of COVID-19. We describe a WarmStart colorimetric reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for the detection of SARSCoV-2. The detection limit for this assay was 1 copy/mu L SARS-CoV-2. To test the clinical sensitivity and specificity of the assay, 37 positive and 20 negative samples were used. The WarmStart colorimetric RT-LAMP had 100% sensitivity and specificity. End products were detected by direct observation, thereby eliminating the need for post-amplification processing steps. WarmStart colorimetric RT-LAMP provides an opportunity to facilitate virus detection in resource limited settings without a sophisticated diagnostic infrastructure.

Automated summary

A novel WarmStart colorimetric RT-LAMP assay for detecting SARS-CoV-2 was developed, showing simplicity, speed, and high sensitivity. Clinical testing with positive and negative samples demonstrated 100% sensitivity and specificity. This detection technology eliminates the need for complex post-amplification processing steps and is suitable for virus detection in resource-limited settings.