Title Development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) thermal inactivation method with preservation of diagnostic sensitivity
Author Young-Il Kim1,2, Mark Anthony B. Casel1,2, Se-Mi Kim1, Seong-Gyu Kim1, Su-Jin Park1,2, Eun-Ha Kim1,2, Hye Won Jeong1, Haryoung Poo3, and Young Ki Choi1,2*
Address 1College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju 28644, Republic of Korea, 2Zoonotic Infectious Diseases Research Center, Chungbuk National University, Cheongju 28644, Republic of Korea, 3Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology, Daejeon 34141, Republic of Korea
Bibliography Journal of Microbiology, 58(10),886–891, 2020,
DOI 10.1007/s12275-020-0335-6
Key Words SARS-CoV-2, heat inactivation, COVID-19, genomic stability, RT-PCR
Abstract Various treatments and agents had been reported to inactivate RNA viruses. Of these, thermal inactivation is generally considered an effective and cheap method of sample preparation for downstream assays. The purpose of this study is to establish a safe inactivation method for SARS-CoV-2 without compromising the amount of amplifiable viral genome necessary for clinical diagnoses. In this study, we demonstrate the infectivity and genomic stability of SARSCoV- 2 by thermal inactivation at both 56°C and 65°C. The results substantiate that viable SARS-CoV-2 is readily inactivated when incubated at 56°C for 30 min or at 65°C for 10 min. qRT-PCR of specimens heat-inactivated at 56°C for 30 min or 65°C for 15 min revealed similar genomic RNA stability compared with non-heat inactivated specimens. Further, we demonstrate that 30 min of thermal inactivation at 56°C could inactivate viable viruses from clinical COVID-19 specimens without attenuating the qRT-PCR diagnostic sensitivity. Heat treatment of clinical specimens from COVID-19 patients at 56°C for 30 min or 65°C for 15 min could be a useful method for the inactivation of a highly contagious agent, SARS-CoV-2. Use of this method would reduce the potential for secondary infections in BSL2 conditions during diagnostic procedures. Importantly, infectious virus can be inactivated in clinical specimens without compromising the sensitivity of the diagnostic RT-PCR assay.