Figure 1

Stability of HCVcc at 37°C, room temperature (25 ± 2°C), and 4°C. Aliquots (300 μl) of an HCVcc stock with an initial infectious titer of 2.5 × 10⁴ FFU/ml were incubated at 37°C (A), room temperature (B), or 4°C (C). In (B) the decay rate of HCVcc infectivity at room temperature was calculated as 0.254-log/day, after the data were fit to a linear regression model (R² = 0.9963). (D). Aliquots of HCVcc diluted in normal human serum (1.0 × 10⁵ FFU/ml) were incubated at room temperature. At indicated time points, viral titers were determined by FFU assay on Huh7-25-CD81 cells and shown as mean log₁₀ FFU/ml ± SD. The dashed line indicates the detection limit of the FFU assay (10 FFU/ml). The asterisks in (A), (B) and (D) denote time points when infectivity was completely lost (tested negative for HCV NS3 expression to the third cell passage).