Infectious stability of Min3 is significantly greater than that of wild-type HCV or the HCV single mutants. Infectivities at various times for the wild type, Min3, core K78E, NS2 W879R, and NS4B V1761L are indicated. Infectious stability (t1/2) was calculated as described in Materials and Methods. For wild-type HCV, t1/2 = 1.5 ± 0.3 h; for Min3, t1/2 = 4.0 ± 0.5 h; for core K78E, t1/2 = 1.3 ± 0.2 h; for NS2 W879R, t1/2 = 1.7 ± 0.3 h; and for NS4B V1761L, t1/2 = 1.9 ± 0.5 h. (B to F) Infectious stability data are shown individually for the wild type, Min3, core K78E, NS2 W879R, and NS4B V1761L virus as bar graphs. Error bars indicate standard deviations of data from 2 assays.