Use of a simplified sample processing step without RNA extraction for direct SARS-CoV-2 RT-PCR detection

J Clin Virol. 2020 Nov;132:104587. doi: 10.1016/j.jcv.2020.104587. Epub 2020 Aug 11.


The severe acute respiratory syndrome coronavirus (SARS-CoV-2) pandemic has resulted in significant shortages of RT-PCR testing supplies including RNA extraction kits. The goal of our study was to determine if a simplified heat-RNA release method would provide comparable detection of SARS-CoV-2 without the need for nucleic acid extraction. RT-PCR results using the ChromaCode HDPCR™ SARS-CoV-2 were compared using the heat-RNA release method and an automated RNA extraction system (EMAG). The heat-RNA release method correctly identified 94 % (81/86 nasopharyngeal samples) that were positive for SARS-CoV-2. Five samples that were missed by heat-RNA release method had a mean Ct value: 35 using the automated extraction instrument, indicating a very low viral load. Our findings show that a simple heat-RNA release method is a reasonable alternative for the majority of COVID-19 positive patients and can help overcome the cost and availability issues of RNA extraction reagents.

Keywords: Extraction; RT-PCR; SARS-CoV-2.

MeSH terms

  • COVID-19 / diagnosis*
  • COVID-19 Testing / methods*
  • Humans
  • RNA, Viral / analysis
  • RNA, Viral / genetics*
  • Real-Time Polymerase Chain Reaction / methods*
  • SARS-CoV-2 / genetics*


  • RNA, Viral