Fast Detection of SARS-CoV-2 RNA Directly from Respiratory Samples Using a Loop-Mediated Isothermal Amplification (LAMP) Test

Viruses

Olympia E. Anastasiou¹  Caroline Holtkamp¹  Anna Maria Eis-Hübinger²  Frieda Schön³  Miriam Schäfer³  Andi Krumbholz³ 

[1] Institute for Virology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;Institute of Virology, Medical Faculty, University Hospital Bonn, 53127 Bonn, Germany;Labor Dr. Krause und Kollegen MVZ GmbH, 24106 Kiel, Germany;

关键词: SARS-CoV-2;    COVID-19;    RT-PCR;    nucleic acids;    direct testing;    loop-mediated isothermal amplification;   

DOI  :  10.3390/v13050801

来源: DOAJ

【 摘 要 】

The availability of simple SARS-CoV-2 detection methods is crucial to contain the COVID-19 pandemic. This study examined whether a commercial LAMP assay can reliably detect SARS-CoV-2 genomes directly in respiratory samples without having to extract nucleic acids (NA) beforehand. Nasopharyngeal swabs (NPS, n = 220) were tested by real-time reverse transcription (RT)-PCR and with the LAMP assay. For RT-PCR, NA were investigated. For LAMP, NA from 26 NPS in viral transport medium (VTM) were tested. The other 194 NPS were analyzed directly without prior NA extraction (140 samples in VTM; 54 dry swab samples stirred in phosphate buffered saline). Ten NPS were tested directly by LAMP using a sous-vide cooking unit. The isothermal assay demonstrated excellent specificity (100%) but moderate sensitivity (68.8%), with a positive predictive value of 1 and a negative predictive value of 0.65 for direct testing of NPS in VTM. The use of dry swabs, even without NA extraction, improved the analytical sensitivity; up to 6% of samples showed signs of inhibition. LAMP could be performed successfully with a sous-vide cooking unit. This technique is very fast, requires little laboratory resources, and can replace rapid antigen tests or verify reactive rapid tests on-site.

【 授权许可】

Unknown