Methods of inactivation of SARS-CoV-2 for downstream biological assays

Abstract

18The scientific community has responded to the COVID-19 pandemic by rapidly undertaking 19 research to find effective strategies to reduce the burden of this disease. Encouragingly, 20 researchers from a diverse array of fields are collectively working towards this goal. Research 21 with infectious SARS-CoV-2 is undertaken in high containment laboratories, however, it is 22 often desirable to work with samples at lower containment levels. To facilitate the transfer of 23 infectious samples from high containment laboratories, we have tested methods commonly 24 used to inactivate virus and prepare the sample for additional experiments. Incubation at 80°C, 25 and a range of detergents and UV energies were successful at inactivating a high titre of 26 SARS-CoV-2. These protocols can provide a framework for in house inactivation of SARS-27CoV-2 in other laboratories, ensuring the safe use of samples in lower containment levels. 28 29

SARS-CoV-2-specific IgA and limited inflammatory cytokines are present in the stool of select patients with acute COVID-19

“…For the measurement of antibodies and cytokines, stool aliquots of 150–600 mg were frozen at −80°C. Samples were thawed on ice and homogenized to a concentration of 500 mg/mL in 1x PBS supplemented with protease inhibitor cocktail (cOmplete EDTA-free, Roche (1 tablet in 10mL) and phenylmethylsulfonyl fluoride (0.3 mM); to prevent protein degradation) and Triton X-100 (0.5% final concentration; to inactivate SARS-CoV-2 virus 43 ). Samples were homogenized by vigorous shaking in a Mini-Beadbeater (Biospec) without beads for 60 seconds, kept on ice for one hour to ensure virus inactivation, centrifuged at 12,000 × g for 20 minutes at 4°C and the supernatants collected.…”

Analysis of Inactivation of SARS-CoV-2 by Specimen Transport Media, Nucleic Acid Extraction Reagents, Detergents, and Fixatives

“…Furthermore, the precise composition of many commercial reagents is proprietary, preventing ingredient-based inference of inactivation efficacy between reagents. Some limited preliminary data on SARS-CoV-2 inactivation by heat (14,15) or chemical (16)(17)(18)(19)(20)(21) Vero E6 cells at a multiplicity of infection (MOI) of 0.001, in the presence of 5% FCS. Cell culture supernatants were collected 72 hours post infection, clarified for 10 mins at 3000 × g, aliquoted and stored at -80°C until required.…”

Inactivation analysis of SARS-CoV-2 by specimen transport media, nucleic acid extraction reagents, detergents and fixatives

“…Furthermore, the precise composition of many commercial reagents is proprietary, preventing ingredient-based inference of inactivation efficacy between reagents. Some limited preliminary data on SARS-CoV-2 inactivation are available (14)(15)(16)(17)(18)(19), but given the current level of diagnostic and research activities, there is an urgent need to comprehensively investigate SARS-CoV-2-specific inactivation efficacy of available methods to support safe virus handling.…”