Sensitivity of the real-time PCR/RT-PCR for the detection of CPV and CDV plasmid standards. Serial 10-fold plasmid dilutions (CPV: 7.44×108 copies·μL-1 to 7.44×100 copies·μL-1; CDV: 4.20×107 copies·μL-1 to 4.20×100 copies·μL-1) were plotted against the threshold cycle (Ct) values. A minimum of 7.44×101 copies of CPV (A) and 4.20×101 copies of CDV (B) were detected. 1–9: Equal dilutions of the CPV plasmid standard at 101–109; 12-19: equal dilutions of the CDV plasmid standard at 101–108; 10, 20: negative control; 11, 21: threshold line.