Fig 2. The persistent strain MNV-S99 is more resistant to antiviral effect of IFN-β, compared to MNV-1.CW3.

RAW264.7 cells were infected with MNV-S99 or MNV-1.CW3 using an MOI of 0.1 TCID₅₀/cell (a) without or in the presence of (b) 10 U/ml IFN-β or (c) 100 U/ml IFN-β. Viral titers in cell culture supernatant were measured by virus titration using the Spearman and Kärber algorithm to calculate the TCID₅₀/ml. Three independent experiments, performed in triplicates were done. Statistical analysis was done by using Wilcoxon signed-rank test, statistically significant differences (p ≤ 0.05) are denoted by asterisks. Dashed line represents the detection limit of the assay.