FIG. 7.

Western blot analysis of purified cores. Wild-type and vif mutant virions produced in HUT78 cells were layered on top of 10 to 60% sucrose gradients containing a layer of 20% sucrose without any detergent (Untreated), 20% sucrose with 0.5% Triton X-100 (Detergent), or 20% sucrose with 0.5% Triton X-100 and 500 mM NaCl (Detergent-NaCl). The gradients were centrifuged for 3 h at 14,000 × g, and fractions were collected from the top. Lanes P represent the pellet. The distribution of viral proteins was analyzed by Western blotting of the fractions. Blots were used for multiple hybridizations and were stripped and reprobed as described in the legend to Fig. 2.