PT Journal
AU Anastasiou, OE
   Holtkamp, C
   Schäfer, M
   Schön, F
   Eis-Hübinger, AM
   Krumbholz, A
TI Fast Detection of SARS-CoV-2 RNA Directly from Respiratory Samples Using a Loop-Mediated Isothermal Amplification (LAMP) Test
SO Viruses
PY 2021
VL 13
IS 5
PU MDPI AG
DI 10.3390/v13050801
WP https://macau.uni-kiel.de/receive/macau_mods_00001505
LA en
DE Nasopharynx; Humans; DNA, Viral; Specimen Handling; Molecular Diagnostic Techniques; Sensitivity and Specificity; Nucleic Acid Amplification Techniques; COVID-19; SARS-CoV-2; COVID-19 Nucleic Acid Testing; Nucleic acids; RT-PCR; LAMP; Loop-mediated Isothermal Amplification; Direct Testing
SN 1999-4915
AB 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.
PI Basel
ER