PLoS ONE (Jan 2021)

Development of a multiplex Loop-Mediated Isothermal Amplification (LAMP) assay for on-site diagnosis of SARS CoV-2.

  • Woong Sik Jang,
  • Da Hye Lim,
  • Jung Yoon,
  • Ahran Kim,
  • Minsup Lim,
  • Jeonghun Nam,
  • Richard Yanagihara,
  • Sook-Won Ryu,
  • Bo Kyeung Jung,
  • Nam-Hee Ryoo,
  • Chae Seung Lim

DOI
https://doi.org/10.1371/journal.pone.0248042
Journal volume & issue
Vol. 16, no. 3
p. e0248042

Abstract

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A newly identified coronavirus, designated as severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), has spread rapidly from its epicenter in China to more than 150 countries across six continents. In this study, we have designed three reverse-transcription loop-mediated isothermal amplification (RT-LAMP) primer sets to detect the RNA-dependent RNA polymerase (RdRP), Envelope (E) and Nucleocapsid protein (N) genes of SARS CoV-2. For one tube reaction, the detection limits for five combination SARS CoV-2 LAMP primer sets (RdRP/E, RdRP/N, E/N, RdRP/E/N and RdRP/N/Internal control (actin beta)) were evaluated with a clinical nasopharyngeal swab sample. Among the five combination, the RdRP/E and RdRP/N/IC multiplex LAMP assays showed low detection limits. The sensitivity and specificity of the RT-LAMP assay were evaluated and compared to that of the widely used Allplex™ 2019-nCoV Assay (Seegene, Inc., Seoul, South Korea) and PowerChek™ 2019-nCoV Real-time PCR kit (Kogenebiotech, Seoul, South Korea) for 130 clinical samples from 91 SARS CoV-2 patients and 162 NP specimens from individuals with (72) and without (90) viral respiratory infections. The multiplex RdRP (FAM)/N (CY5)/IC (Hex) RT-LAMP assay showed comparable sensitivities (RdRP: 93.85%, N: 94.62% and RdRP/N: 96.92%) to that of the Allplex™ 2019-nCoV Assay (100%) and superior to those of PowerChek™ 2019-nCoV Real-time PCR kit (RdRP: 92.31%, E: 93.85% and RdRP/E: 95.38%).