FIG 2.

Infectious progeny production of hepatitis C virus populations passaged in the absence or presence of sofosbuvir. HCV p0, HCV p45, and HCV p100 were subjected to 10 serial passages in the absence (no drug) or the presence of 800 nM or 1,200 nM sofosbuvir (SOF). For the first passage, 4 × 10⁵ Huh-7.5 reporter cells were infected with 1.2 × 10⁴ TCID₅₀ of the indicated virus, to give a multiplicity of infection (MOI) of 0.03 TCID₅₀/cell. For successive infections, 4 × 10⁵ Huh-7.5 reporter cells were infected with the virus contained in 500 μl of the cell culture supernatant from the previous infection, yielding a range of MOIs of 1.25 × 10⁻⁵ to 3.95 TCID₅₀/cell. Infections were allowed to proceed for 72 h. The abscissa axes indicate the limits of detection of virus titers. Infection conditions are further detailed in Materials and Methods.