High sensitivity-low cost detection of SARS-CoV-2 by two steps end point RT-PCR with agarose gel electrophoresis visualization

Sci Rep. 2021 Nov 4;11(1):21658. doi: 10.1038/s41598-021-00900-8.

Abstract

More than one year since Coronavirus disease 2019 (COVID-19) pandemic outbreak, the gold standard technique for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection is still the RT-qPCR. This is a limitation to increase testing capacities, particularly at developing countries, as expensive reagents and equipment are required. We developed a two steps end point RT-PCR reaction with SARS-CoV-2 Nucleocapsid (N) gene and Ribonuclease P (RNase P) specific primers where viral amplicons were verified by agarose gel electrophoresis. We carried out a clinical performance and analytical sensitivity evaluation for this two-steps end point RT-PCR method with 242 nasopharyngeal samples using the CDC RT-qPCR protocol as a gold standard technique. With a specificity of 95.8%, a sensitivity of 95.1%, and a limit of detection of 20 viral RNA copies/uL, this two steps end point RT-PCR assay is an affordable and reliable method for SARS-CoV-2 detection. This protocol would allow to extend COVID-19 diagnosis to basic molecular biology laboratories with a potential positive impact in surveillance programs at developing countries.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19 / diagnosis*
  • COVID-19 / genetics
  • COVID-19 Nucleic Acid Testing / economics
  • COVID-19 Nucleic Acid Testing / methods*
  • COVID-19 Testing / methods
  • Coronavirus Nucleocapsid Proteins / genetics
  • DNA Primers
  • Electrophoresis, Agar Gel / methods
  • Humans
  • Laboratories
  • Nasopharynx / virology
  • RNA, Viral / genetics
  • Ribonuclease P / genetics
  • Ribonuclease P / metabolism
  • SARS-CoV-2 / genetics*
  • SARS-CoV-2 / pathogenicity
  • Sensitivity and Specificity

Substances

  • Coronavirus Nucleocapsid Proteins
  • DNA Primers
  • RNA, Viral
  • Ribonuclease P