Fig 3.

Concentration dependence curves for toxin neutralization by the combination of MAbs AVR1046 and F20G75. The concentration of one antibody was varied in the manner indicated on the x axis, while that of the other was held constant. Cell viability is indicated for concentrations of the serially diluted antibody assayed either individually or combined with the other MAb held constant at the concentration indicated. Neutralization obtained with the antibody that was held constant in the absence of the serially diluted antibody is indicated on the y axis. In panel B, assays were conducted in the presence of the Fcγ receptor-blocking antibody MAb 2.4G2 as described in Materials and Methods. Each point corresponds to the mean of the values obtained for three independent sample preparations run on the same plate, with the SD indicated by the error bar. For each independent assay, the samples were run on duplicate plates. Each curve is representative of independent assays each run on at least three different days.