FIG 2.

The fraction of antibody adopting a lower diffusion rate in FCS is virion dose dependent. The indicated viruses were titrated as a function of p24 antigen equivalents (see Materials and Methods) and incubated with a fixed quantity of Alexa Fluor 647-labeled MAb b12 (6.6 μg/ml). The relative fraction of MAb b12 that exhibits a lower diffusion coefficient (∼8 μm²/s) as a result of virion binding in solution (see Materials and Methods) is shown. All experiments were repeated three times, and average values are shown. Error bars indicate standard deviations.