Cell transfection with the different DNA-based vaccine candidates. Cells were transfected with pCMV3ISS-GPV (A1); pCMV3ISS-CDVH (A2); pCMV3ISS-GPV and pCMV3ISS-CDVH (B1 and 2); pCMV3ISS-GPV-CDVH (C1 and 2); pCMV3ISS-GPV-2A-CDVH (D1 and 2); pCMV3ISS-GPV-IRES-CDVH (E1 and 2); and pCMV3ISS (F1 and 2). A-F1, were first incubated with a murine anti-rabies glycoprotein monoclonal antibody, then with anti-IgG of mouse conjugated with FITC. A-F2 incubated with anti-CDV polyclonal antibodies produced in dogs, then with anti-IgG of dog FITC conjugated. Cells were observed under a fluorescent microscope (original magnification × 400).