Fig. 3

An IFA verified the antiviral effect of copper chloride. a F81 cells were infected with different concentrations of copper chloride (20–200 μM) and FCV (100 TCID₅₀), and a mock treatment group containing 0.4% DMSO and a negative control group that was not infected with FCV were used as controls. After incubation for 1 h at 37 °C in 5% CO₂, an IFA of the F81 cells was performed. b Two experimental wells were selected in the 96-well cell plate, and the fluorescence signals were detected in randomly selected areas in each well using ImageJ software. The experimental result was expressed as the average of two fluorescence signals. The antiviral effect of copper chloride was evaluated by detecting the fluorescence signal; **** p < 0.0001