A Rapid, Highly Sensitive and Open-Access SARS-CoV-2 Detection Assay for Laboratory and Home Testing

RT-qPCR-based diagnostic tests play important roles in combating virus-caused pandemics such as Covid-19. However, their dependence on sophisticated equipment and the associated costs often limits their widespread use. Loop-mediated isothermal amplification after reverse transcription (RT-LAMP) is an alternative nucleic acid detection method that overcomes these limitations. Here, we present a rapid, robust, and sensitive RT-LAMP-based SARS-CoV-2 detection assay. Our 40-min procedure bypasses the RNA isolation step, is insensitive to carryover contamination, and uses a colorimetric readout that enables robust SARS-CoV-2 detection from various sample types. Based on this assay, we have increased sensitivity and scalability by adding a nucleic acid enrichment step (Bead-LAMP), developed a version for home testing (HomeDip-LAMP), and identified open-source RT-LAMP enzymes that can be produced in any molecular biology laboratory. On a dedicated website, rtlamp.org (DOI: 10.5281/zenodo.6033689), we provide detailed protocols and videos. Our optimized, general-purpose RT-LAMP assay is an important step toward population-scale SARS-CoV-2 testing.MK was supported by the Vienna Science and Technology Fund (WWTF) through project COV20-031 (to JZ) and a Cambridge Trust LMB Cambridge Scholarship. Research in the AP lab is supported by the Austrian Science Fund (START Projekt Y 1031-B28, SFB “RNA-Deco” F 80) and EMBO-YIP; research in the JB lab is supported by the European Research Council (ERC- 2015-CoG - 682181). The IMP receives generous institutional funding from Boehringer Ingelheim and the Austrian Research Promotion Agency (Headquarter grant FFG-852936); IMBA is generously supported by the Austrian Academy of Sciences. Work in the LM-A laboratory is supported by grant PID2019- 104176RB-I00/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation, and an institutional grant of the Fundación Ramón Areces.Peer reviewe

A rapid, highly sensitive and open-access SARS-CoV-2 detection assay for laboratory and home testing

Global efforts to combat the Covid-19 pandemic caused by the beta coronavirus SARS-CoV-2 are currently based on RT-qPCR-based diagnostic tests. However, their high cost, moderate throughput and reliance on sophisticated equipment limit widespread implementation. Loop-mediated isothermal amplification after reverse transcription (RT-LAMP) is an alternative detection method that has the potential to overcome these limitations. Here we present a rapid, robust, highly sensitive and versatile RT-LAMP based SARS-CoV-2 detection assay. Our forty-minute procedure bypasses a dedicated RNA isolation step, is insensitive to carry-over contamination, and uses a hydroxynaphthol blue (HNB)-based colorimetric readout, which allows robust SARS-CoV-2 detection from various sample types. Based on this assay, we have substantially increased sensitivity and scalability by a simple nucleic acid enrichment step (bead-LAMP), established a pipette-free version for home testing (HomeDip-LAMP), and developed a version with open source enzymes that can be produced in any molecular biology setting. Our advanced, universally applicable RT-LAMP assay is a major step towards population-scale SARS-CoV-2 testing.N