FIG. 3.

Neutralization curves for 2F5 and 2G12 antibodies against primary isolates. The dose-dependent inhibition of primary isolates was assessed by measuring p24 concentrations in HIV-infected PBMC cultures. The antibody dilutions (in micrograms/milliliter) are plotted against the p24 levels relative to p24 in the blank (without addition of antibody) (V_n/V₀). The horizontal lines on the y axes indicate the points of 50, 90, and 99% virus reduction. The primary isolates used were P7/366 (A), S2/04 (B), P3/366 (C), and P2/71 (D). MAb, monoclonal antibody.