Concentration of infectious SARS-CoV-2 by polyethylene glycol precipitation

• Published in: Journal of virological methods Vol. 286; p. 113977
• Main Authors: Alexander, Marina R., Rootes, Christina L., van Vuren, Petrus Jansen, Stewart, Cameron R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2020; Published by Elsevier B.V
• Subjects: Animals; Betacoronavirus - isolation & purification; Caco-2 Cells; Chlorocebus aethiops; Clinical Laboratory Techniques - methods; Coronavirus Infections - diagnosis; Coronavirus Infections - virology; COVID-19; COVID-19 Testing; Humans; Pandemics; PEG precipitation; Pneumonia, Viral - diagnosis; Pneumonia, Viral - virology; Polyethylene Glycols - chemistry; Reverse Transcriptase Polymerase Chain Reaction; SARS-CoV-2; Short Communication; Ultracentrifugation - methods; Vero Cells; Virus concentration; COVID-19; PEG precipitation; Virus concentration; SARS-CoV-2
• ISSN: 0166-0934; 1879-0984
• DOI: 10.1016/j.jviromet.2020.113977

•Polyethylene glycol (PEG)-mediated precipitation is an established methodology for concentration of virus stocks and is applied here to SARS-COV-2 derived from VeroE6 supernatant.•PEG precipitation resulted in a 1.5log10 increase in SARS-CoV-2 infectious titres in VeroE6, Calu-3 and Caco-2 cells.•This protocol is a simple and reliable methodology for the concentration of SARS-COV-2 stocks for a range of virology applications. The development of medical countermeasures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires robust viral assays. Here we have adapted a protocol for polyethylene glycol (PEG)-mediated precipitation of SARS-CoV-2 stocks without the need for ultracentrifugation. Virus precipitation resulted in a ∼1.5 log10 increase in SARS-CoV-2 titres of virus prepared in VeroE6 cells and enabled the infection of several immortalized human cell lines (Caco-2 and Calu-3) at a high multiplicity of infection not practically achievable without virus concentration. This protocol underscores the utility of PEG-mediated precipitation for SARS-CoV-2 and provides a resource for a range of coronavirus research areas.