Fig. 3

IFA results of PK cells infected by PCV2 rescued viruses. a Shown were representative IFA images (Magnification: 20 × 10, Olympus), NC, negative control; PC, positive control. b Quantification of PK15 cells infected by PCV2 viruses (n = 5). Results were expressed as mean ± SD. IFA assays were independently repeated three times. **represents statistical significance P<0.01 between indicated groups