FIG. 6.

Biophysical properties of the infectious particles present in the Huh-7 cell-lysates. Infected cell lysates were subjected to ultracentrifugation as described in Materials and Methods. (A) Representative sedimentation velocity profile of the infectious viral particles in the supernatant (focus-forming units [FFU]/ml, black diamonds) and the cell lysate (FFU/ml, white squares) in continuous gradients of 10 to 50% sucrose. (B) Representative buoyant density profile of viral infectivity in the supernatant (black diamonds) and in the cell lysate (open squares) in 10 to 50% iodixanol step gradients. The dotted line represents the density (g/ml) measured in each fraction.