Characterization of the JEV replicon. (A) BHK-21 cells transfected with the JEV replicon pJE3Rep were subjected to indirect immunofluorescence assay (IFA). JEV viral proteins were visualized using NS1- and E-specific mouse monoclonal antibody and stained with fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG at 72 h post-transfection. The green signals represent FITC-positive cells. Viral RNAs (JEV) and PBS (Mock) were set as controls. (B) RT-PCR targeted at the prM/E genes (Lane 1, 3 and 5) and NS3 genes (Lane 2, 4 and 6). The amplified products for NS3 and prM/E gene were 1185 and 1208 bp, respectively. Total RNAs were extracted from BHK-21 cells at 72 h post transfection. Viral RNAs (JEV) and PBS (Mock) were set as controls.