Fig. 1. Production of SARS-CoV-2 VLPs by transient transfection. (A) Schematic outline of SARS-CoV-2 VLPs generation in HEK293T cells transfected with SARS-CoV-2 structural protein-expressing plasmids. (B) Western blot analysis of VLPs in supernatants of transfected cells. SARS-CoV-2 proteins present in whole cell lysates (WCLs) and ultracentrifuged supernatants (UCF) 48 h after transfection with the indicated plasmids, and detected using anti-S and anti-N antibodies. Protein size markers are shown. This experiment is representative of two independent replicates. (C) Electron microscopy detection of SARS-CoV-2 VLPs. Supernatants of transfected HEK293T cells were collected 48 h after transfections, purified, fixed, concentrated by ultracentrifugation and processed for EM analysis. Scale bar = 100 nm.