FIG. 1.

Replication of HCV genotype 1a (clone H77) after serial passage in IHH. The HCV replication and secretion of virus in culture medium were examined using different parameters. The relative copy number of HCV RNA at the intracellular level and in culture supernatant were measured by real-time PCR and calculated as described in Materials and Methods. The results are presented with standard errors from three independent experiments. Mock-infected or HCV-infected IHH culture supernatant was tested for core protein detection by ELISA. HCV titer (ffu/ml) was determined by the immunofluorescence of IHH 3 days after infection with filtered culture medium for the detection of NS4 protein expression. Relative HCV RNA in cell culture fluid (black bars) and HCV GAPDH ratio in cellular RNA (white bars) are shown. Infectivity (ffu/ml) is shown as a green line, and core protein level is shown on top.