FIG. 4.

Reproducibility of HCV infection in nondividing Huh7 cell cultures. Huh7 cells were plated in a 96-well format, DMSO-treated for 20 days, and then infected with HCVcc JFH-1 at an MOI of 0.05 FFU/cell. (A) HCV RNA and NS3 protease activity were measured 6 days p.i. in 42 replicates. Intracellular HCV RNA was analyzed by RTqPCR and displayed as HCV RNA copies/μg total cellular RNA. NS3 protease activity, expressed as RFU, was determined by FRET analysis. (B) HCVcc infectivity titers on days 3, 5, 7, and 25 p.i., expressed as FFU/ml, were determined by immunohistochemical analysis of 10-fold serially diluted culture supernatant replicates on naïve Huh7 cells.