Mouse monoclonal antibody against sars cov 1 2 nucleoprotein clone 1c7c7

Neutralization activities of SARS-CoV-2 were determined by using an FRNT as previously described^{15 (link)}. Serial dilutions of plasma were mixed with 1,000 focus-forming units of virus per well and incubated for 1 h at 37 °C. The antibody-virus mixture was inoculated on VeroE6/TMPRSS2 cells in 96-well plates in duplicate and incubated for 1 h at 37 °C. An equal volume of 1.2% Avicel RC-581 (DuPont Nutrition) in culture medium was added to each well. The cells were incubated for 24 h at 37 °C and then fixed with formalin. After the formalin was removed, the cells were immunostained with a mouse monoclonal antibody against SARS-CoV-1/2 nucleoprotein (clone 1C7C7 (Sigma-Aldrich)) (1:2,000 dilution), followed bya horseradish peroxidase-labelled goat anti-mouse immunoglobulin (SeraCare Life Sciences) (1:2,000 dilution). The infected cells were stained with TrueBlue Substrate (SeraCare Life Sciences) and then washed with distilled water. After cell drying, the focus numbers were quantified by using an ImmunoSpot S6 Analyzer, ImmunoCapture software, and BioSpot software (Cellular Technology). The results are expressed as the 50% focus reduction neutralization titre (FRNT₅₀). The FRNT₅₀ values were calculated by using GraphPad Prism (GraphPad Software).