Fig. 4

The antiviral effect of copper chloride on FCV at different time points. F81 cells were infected with 100 TCID₅₀ FCV and then treated with 80 μM copper chloride for − 1, 0, 1, 2, 4, 8, and 16 h. After incubation for 24 h at 37 °C in 5% CO₂, the virus titre (a) and relative RNA levels (b) of FCV were detected. NS, p > 0.1234; ** p < 0.0021; *** p < 0.0002; and **** p < 0.0001. (‘-1 h’ indicates that the cells were treated with CuCl₂ 1 h before infection)