LAMP Assay for On-site Detection of SARS-CoV-2 and Its Application in Cold-chain Food Analysis

ABSTRACT

A highly sensitive visualization method for SARS-CoV-2 detection, based on loop-mediated isothermal amplification (LAMP) and molecular light switch [Ru(phen)2dppz]2+, was established. In this design, insulation cups replaced laboratory thermostats and blue flashlights replaced blue transilluminators, to realize the rapid on-site visual LAMP detection of SARS-CoV-2. Specific primers were designed for the N gene of SARS-CoV-2. LAMP amplification products were detected by [Ru(phen)2dppz]2+ with molecular light switch characteristics. Red fluorescence could be directly detected by naked eye using blue light flashlight. Single copy number SARS-CoV-2 gene fragments were detected with high specificity. The detection was rapid, requiring only 40 minutes to visually observe the results. The LAMP detection results for food samples artificially contaminated with SARS-CoV-2 pseudovirus were 100% consistent with the current gold-standard real-time fluorescent quantitative PCR method for SARS-CoV-2 detection. This method requires only insulation cups and blue flashlight, and can be used to supplement the real-time fluorescent PCR method to provide a fast and efficient on-site screening of food for SARS-CoV-2. © 2022, Editorial Board of Modern Food Science and Technology. All right reserved.