Portable nucleic acid tests for rapid detection of monkeypox virus

ABSTRACT We report two isothermal nucleic acid amplification assays for detection of monkeypox virus (MPXV) clades 2 and 3 that include the strains responsible for the current global outbreak of monkeypox. The assays use loop-mediated isothermal amplification (LAMP) to amplify two distinct sequences in the MPXV genome. Readout specificity is ensured by oligonucleotide strand displacement (OSD) probes integrated in one-pot LAMP-OSD reactions. OSD probes undergo toehold-mediated strand displacement hybridization to LAMP amplicon loop sequences derived from MPXV clades 2 and 3 resulting in fluorescence readable both in realtime and visually at endpoint. We also perform both assays on two different portable devices, the GeneTiger and the miniPCR, to exemplify compatibility with minimum infrastructure point-of-care (POC) testing in clinical and at-home settings. Both assays could readily detect single digit copies of MPXV synthetic double stranded DNA templates within 30 min.