Fig. 3.

Infection and proliferation characteristics of PEAV in IPI-2I cells. (A) IPI-2I cells were mock-infected or infected with PEAV at a MOI of 1. Cytopathic effect was observed at 6, 12, 18, 24 and 30 hpi. (B) The infected IPI-2I cells were fixed at different time points post-infection and indirect immunofluorescence assay was performed with a monoclonal antibody against PEAV S protein. (C) IPI-2I cells or Vero cells were infected with PEAV (MOI = 0.1). The trypsin concentrations used in IPI-2I cells and Vero cells were 2.5 μg/ml and 7.5 μg/ml, respectively. Cell were collected at 6, 12, 18, 24 and 30 hpi to determine the viral titers by TCID₅₀ assay.