Surface detection of SARS-CoV-2 by lateral flow LAMP

Abstract

Slowing the transmission of SARS-CoV-2 requires rapid and accurate diagnostic testing. Toward this end, loop-mediated isothermal amplification (LAMP), an isothermal genomic detection method, offers great promise but the readout tends to be difficult because it does not generate linear DNA products. Rapid antigen tests are coupled to lateral flow strips, with one (negative) or two (positive) bands providing simple rapid readout, but are less sensitive than genomic amplification methods. To address the need for a genomic amplification method that can be visualized on a lateral flow strip, we developed a novel strand-displacement probe. In this work we validate this pipeline for purified RNA, intact virus, and even virus deposited onto a surface. We demonstrate robust sensitivity (100 genomic copies) and and we demonstrate the utility of our assay as a surveillance system, with the capability to detect viral particles from surfaces, even after a week of complete dry-down. Our innovation couples the diagnostic advantages of a nucleic acid amplification test (NAAT) with the simplicity of lateral-flow readouts.