FIG. 4.

Nine-day HCV replicon clearance assay. HCV replicon cells were incubated with various concentrations of VX-950 (A) or BILN 2061 (B) for 3, 6, or 9 days. Fresh protease inhibitors were added to the medium every 3 days. At the end of each incubation period, cell numbers were determined by the tetrazolium (MTS)-based cell viability assay with an established standard curve, and the level of HCV RNA in the cells was determined by the QRT-PCR assay. The HCV RNA copy number per cell in each sample is plotted as an n-fold value (on a log₁₀ scale) of the copy number in replicon cells incubated with 0.2% DMSO (no-compound control) for the same period of time. Each datum point represents the average and SD for five cell culture replicates.