Methods of SARS-CoV-2 Inactivation.

Inactivation methods allow for hazard group 3 (HG3) pathogens to be disposed of and used safely in downstream experiments and assays to be carried out at lower containment levels. Commonly used viral inactivation methods include heat inactivation, fixation methods, ultraviolet (UV) light and detergent inactivation. Here we describe known methods used to inactivate SARS-CoV-2 for safe downstream biological assays.

TRIzol-based RNA extraction for detection protocol for SARS-CoV-2 of coronavirus disease 2019.

Diagnostic testing is important for managing the 2019 novel coronavirus (SARS-CoV-2). We developed an optimized protocol for SARS-CoV-2 RNA extraction from the surface of the respiratory mucosa with nasopharyngeal swabs and compared the sensitivity of RNA extraction methods. RNA extraction was performed using three different procedures (TRIzol, QIAamp, VMT-TRIzol) from nine positive SARS-CoV-2 samples. SARS-CoV-2 was detected by real-time reverse transcriptase PCR (RT-PCR) using a detection kit for SARS-CoV-2 (Sun Yat-sen University). Compared to RT-PCR results, there were no discernible differences in detection rates when comparing the three different extraction procedures. On the basis of these results, the use of TRIzol as a transport medium and RNA extraction method for SARS-CoV-2 detection may be a helpful alternative for laboratories facing shortages of commercial testing kits.

Methods of Inactivation of SARS-CoV-2 for Downstream Biological Assays.

The scientific community has responded to the coronavirus disease 2019 (COVID-19) pandemic by rapidly undertaking research to find effective strategies to reduce the burden of this disease. Encouragingly, researchers from a diverse array of fields are collectively working towards this goal. Research with infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is undertaken in high-containment laboratories; however, it is often desirable to work with samples at lower-containment levels. To facilitate the transfer of infectious samples from high-containment laboratories, we have tested methods commonly used to inactivate virus and prepare the sample for additional experiments. Incubation at 80°C, a range of detergents, Trizol reagents, and UV energies were successful at inactivating a high titer of SARS-CoV-2. Methanol and paraformaldehyde incubation of infected cells also inactivated the virus. These protocols can provide a framework for in-house inactivation of SARS-CoV-2 in other laboratories, ensuring the safe use of samples in lower-containment levels.