Fig 1.

Growth comparison of the wild type (wt) and the cell culture-adapted HCV variant. (A) Cell culture-adapted HCV variant with an infectious titer higher than that of wild-type virus. Huh-7.5 cells were transfected with 2 μg of wild-type or adapted HCV RNAs. The supernatants were collected at 24, 48, 72, and 96 h posttransfection. The infectious HCV titers in the supernatant were determined by serial dilution and IFA. Results shown represents means ± standard deviations for three different experiments. (B) Growth curves of the wild-type and cell culture-adapted HCVs. Huh-7.5 cells in 24-well plates were infected with wild-type and cell culture-adapted HCV at a multiplicity of infection (MOI) of 0.2. The infectious HCV titers (FFU/ml) at different time points (24, 48, 72, and 96 h) postinfection were determined by serial dilution and immunostaining of the HCV-infected cells by IFA as described in Materials and Methods.