Development of a large scale human complement source for use in bacterial immunoassays

► Human plasma or sera are used as a complement source for evaluation of vaccine-induced immune response assays. ► Donors have high levels of antibody which interfere with the measurement of vaccine-mediated responses. ► We have developed a large-scale IgG-depletion process to deplete plasma so that it retains complement activity. ► Use of this IgG-depleted plasma allows multiple strains to be analysed with the same complement source. ► We have demonstrated reproducibility between batches.