Frontiers in Medicine (Feb 2021)

SARS-CoV-2 Direct Detection Without RNA Isolation With Loop-Mediated Isothermal Amplification (LAMP) and CRISPR-Cas12

  • Alfredo Garcia-Venzor,
  • Bertha Rueda-Zarazua,
  • Eduardo Marquez-Garcia,
  • Vilma Maldonado,
  • Angelica Moncada-Morales,
  • Hiram Olivera,
  • Irma Lopez,
  • Joaquin Zuñiga,
  • Jorge Melendez-Zajgla

DOI
https://doi.org/10.3389/fmed.2021.627679
Journal volume & issue
Vol. 8

Abstract

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As to date, more than 49 million confirmed cases of Coronavirus Disease 19 (COVID-19) have been reported worldwide. Current diagnostic protocols use qRT-PCR for viral RNA detection, which is expensive and requires sophisticated equipment, trained personnel and previous RNA extraction. For this reason, we need a faster, direct and more versatile detection method for better epidemiological management of the COVID-19 outbreak. In this work, we propose a direct method without RNA extraction, based on the Loop-mediated isothermal amplification (LAMP) and Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated protein (CRISPR-Cas12) technique that allows the fast detection of SARS-CoV-2 from patient samples with high sensitivity and specificity. We obtained a limit of detection of 16 copies/μL with high specificity and at an affordable cost. The diagnostic test readout can be done with a real-time PCR thermocycler or with the naked eye in a blue-light transilluminator. Our method has been evaluated on a small set of clinical samples with promising results.

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