*2.7. Time of Addition and Dilution Experiment*

PK-15 cell was pre-exposed to EGCG or Opti-MEM medium at 37 ◦C for 60 min, then washed and infected with PCV2 at a MOI = 1.0 at 37 ◦C for 1 h before the inocula were removed, the samples were maintained without EGCG and the infectivity was assessed at 72 hpi. Alternatively, the PCV2 was premixed with EGCG under the same condition before being added to cells, the samples were maintained and determined with same way. For post-treatment samples, cells were first inoculated with PCV2 at a MOI = 1.0 at 37 ◦C, followed by 100 μM EGCG treatment maintained for 4 h, 12 h and 24 h, respectively, the samples were tested at 72 hpi. For dilution experiments, approximately MOI = 10.0 of enriched virions were pretreated with 100 μM EGCG for 60 min at 37 ◦C, and then diluted 10-fold before being added to cell monolayers, infected cell samples were maintained without EGCG after the inocula were removed 1 h. Infectivity of samples was assessed at 72 hpi.
