Analysis of the binding of human (a) CD64, (b) CD32A, (c) CD16/V158 and (d) C1q to mAb 3649 and 3649/TM. Measurements were carried out using an ELISA format as described in §2. Errors were estimated as the standard deviations of at least two individual measurements for each interacting pair. The illegibility of the error bars for some data points is the direct result of the corresponding very low standard deviations. Data shown are representative of at least two independent series of experiments.