FIG. 9.
Heat treatment of HIV-1 MN/H9 cl.4. Virus was incubated at 4, 50, 55, 60, and 65°C for 1 h, and one sample was subjected to freezing and thawing three times. After incubation at various temperatures, viral samples were centrifuged, and pellets were analyzed for gp120 content using HPLC methods (A) under reducing conditions. Peaks were detected at 280 nm. (B) immunoblot analysis of gp120 retention by heat-treated HIV-1MN/H9 cl.4 virus. Virion-associated gp120 and p24CA levels were analyzed by SDS-PAGE under both reducing (R) and nonreducing (NR) conditions, followed by immunoblot analysis. Bands were visualized with mouse monoclonal antibodies prepared against purified p24 and gp120, followed by enhanced chemiluminescence staining.