Scheme of the CAP pre-treatment of cells for SARS-CoV-2 virus infection and the associated results. (A) Conceptual scheme illustrating the protocol used in the SARS-CoV-2 virus experiments. Vero E6 cells were pre-treated with non-toxic concentrations of plasma-activated medium (PAM), 10% PAM or 0% PAM (as control) for 10 minutes prior to SARS-CoV-2-infection with dilutions of stock virus (10E6.79 TCID50/mL virus) as indicated. Cells were incubated with 10% FCS RPMI-1640 medium for 24 hours before fixation and assessment of cell number and area, imaging, immunofluorescence and SEM; (B) Scanning electron microscopy under different folds of magnification showing extracellular virus on Vero E6 cells that underwent 0% PAM or 10% PAM pre-treatment prior to the infection with 1/104 dilution of 10E6.79 TCID50/mL SARS-CoV-2 virus. Extracellular viral particles are pseudocoloured in yellow; (C) Immunofluorescence for ACE2 (green) or SARS-CoV-2 viral particles (yellow), and staining for actin filaments (phalloidin; red) or DNA (Hoechst 33342; blue). Results were analyzed using the Incell 6500HS confocal high content screening microscope, and analyzed using the IN Carta Analysis software for automated unbiased analysis in a plane through the middle of the nucleus to assess staining within the cell or at the periphery.