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

Kellner, Max J.; Ross, James J.; Schnabl, Jakob; Dekens, Marcus P.S.; Heinen, Robert; Grishkovskaya, Irina; Bauer, Benedikt; Stadlmann, Johannes; Menéndez-Arias, Luis; Straw, Andrew D.; Fritsche-Polanz, Robert; Traugott, Marianna; Seitz, Tamara; Zoufaly, Alexander; Födinger, Manuela; Wenisch, Christoph; Zuber, Johannes; Pauli, Andrea; Brennecke, Julius

Global efforts to combat the Covid-19 pandemic caused by SARS-CoV-2 still heavily rely 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. We present a rapid, robust, 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 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.