FIG. 3.

ADCC assay results obtained by using Na₂⁵¹CrO₄-labeled SF2-infected targets in the presence of various numbers of cold-target cells. Various numbers of unlabeled cells were preincubated with 26 μg of 4117C MAb per ml, while the standard number of labeled targets (10⁴ cells) was separately preincubated with the same amount of 4117C MAb. Following this preincubation, the labeled target-MAb mixture was added to the unlabeled target-MAb (cold-target) mixture, attaining the cold-target cell-per-milliliter concentrations shown in the figure. The remainder of the ADCC assay was carried out as previously described (1). The error bars represent standard deviations of duplicate points.