Growth of HCV in 300 μM ribavirin for one week. Huh7D cells were mock infected or infected with wild type J6/JFH1 or HCV-RR2 at a m.o.i. of 0.01. After 6 hours, cells were washed with growth medium three times and passed by tripsinization to 12 well plates containing a final concentration of zero or 300 μM ribavirin. Cells were collected at the indicated time points and frozen at -70°C. Virus was tittered as described in the text. Titers are expressed as the mean number of foci of each of four replicates. Error bars represent the standard deviation.