FIG. 10.

Analysis of virus cores. Viruses collected from transfected cells were treated with 0.3% NP-40 for 10 min, layered onto an equal volume of 20% sucrose, and centrifuged at 120,000 × g for 60 min at 4°C. Top fractions (A), bottom fractions (B), and virus core-containing pellet fractions (C) were collected and subjected in parallel to RT assays (bottom panel) as well as SDS-PAGE and immunoblotting with anti-HIV-1-CA antibody. PrGag and mature CA bands are indicated on the immunoblots. RT units were determined by comparison with activities of known amounts of avian myeloblastosis virus RT.