Regulations governing the production of biopharmaceuticals require high levels of purity for processes utilizing Protein A affinity chromatography. It has been shown that Protein A in the presence of IgG forms a PA/IgG complex that interferes in the traditional immunoassay format for detecting Protein A. In this work we evaluated the AMMP Protein A Assay using two popular sample preparation methods to dissociate the ProteinA/IgG complex. The AMMP assay was also tested with Protein A ligands from multiple sources including…