Inhibition of mast cell migration to C5a by an anticomplement receptor MoAb. HMC-1 cells were incubated for 90 minutes with the anti-C5a receptor MoAb S5/1 at 5 × 10⁻⁷ mol/L. Cells were then washed and migration to 0.1 μg/mL (10 nmol/L) C5a was examined in Boyden chambers. Results are expressed as mean ± SEM of 2 to 10 experiments performed in triplicate (total n = 6 to 10). No migration was observed when cells were stimulated with MoAbs alone.