Protocol for antibody-dependent cellular phagocytosis assay with controlled IgG concentrations in tested samples

Here, we present a protocol to equalize antibody concentrations between samples to focus analysis on IgG properties rather than phagocytosis driven by antibody concentration. We describe steps for quantitating antigen-specific IgG in serum using a suitable binding assay, diluting samples to equalize IgG concentration, and using the antibody-dependent cellular phagocytosis (ADCP) assay. We then detail procedures for measuring differences in antibody properties between experimental groups by running diluted samples in the ADCP assay or other effector function assays. For complete details on the use and execution of this protocol, please refer to St. Germain et al.¹.