Quantifying PEDV Infection in Vero Cells

Vero cells were fixed with 4% paraformaldehyde in phosphate-buffered saline (PBS) (Solarbio) followed by incubating with blocking buffer (0.2% skim milk, 2% FBS, 0.1 M glycine, 1% bovine albumin, and 0.01% triton-X 100 in PBS) for 30 min after incubating with PEDV N protein monoclonal antibody (1:500) for 1 h, followed by the incubation with fluorescence-conjugated goat anti-mouse IgG (1:1000) (Zhongshan, Beijing, China) and 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride (DAPI) (Solarbio) for 30 min. Fluorescence signals were captured with a Ti-S fluorescence microscope (Nikon, Tokyo, Japan). The percentage of viral infected cells was calculated by counting the cells with PEDV N-positive signal and dividing it by the number of DAPI-positive [10 (link)]. For each condition, we chose at least three views with more than 300 DAPI-positive cells and triplicated them to get the standard deviation.