Figure 6

Effect of anionic polymeric microbicide candidates on the integrity of HIV-1 IIIB and BaL virus particles. Purified HIV-1 IIIB (7 × 10⁹ particles/100 μl) and BaL (2.5 × 10⁹ particles/100 μl) untreated or treated with the polymeric substances shown on the abscissa (final concentrations 5 mg/ml except for Carbomer 974P {2.5 mg/ml}) for 5 min at 37°C. The mixtures were cooled on ice and the virus particles were pelletted by centrifugation (1 h at 14,000 rpm in a Beckman 5415 C microfuge). The pellets were resuspended in lysis buffer (1% NP40, 100 μg/ml BSA in PBS) and incubated for 30 min at 37°C. p24 antigen was determined in serial dilutions of the lysates by ELISA. The levels of p24 antigen in the treated virus preparations were compared with those corresponding to lysed untreated virus (= 100%).