Fig. 3

The immunofluorescence assay (IFA) of S-expressing BmN cells (S-Bm Cell). The BmN cells were inoculated with 10 multiplicity of infection (MOI) of the S-Bm and incubated for 48 h. The BmN cells without the inoculation were used as negative control (Mock). The cells were fixed with 4% paraformaldehyde and blocked with 3% BSA for 1 h. After washing with PBS, the S-expressing BmN cells (S-Bm cells) and the mock-inoculated BmN cells were probed with the anti-PEDV S monoclonal antibodies, P4B-1, for 1 h. Following the wash procedure with PBS, the goat anti-mouse IgG conjugated with Alexa Fluor 555 was used as secondary antibody. The Hoechst mounting solution was also used to demonstrate the nuclei. The fluorescence was observed under microscope