Evaluating AMMP Protein A Assays: Comparing Sample Preparation Methods, Ligand Performance & Assay Performance

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 two US Pharmacopeia standards to demonstrate the performance of the assay against the most prevalent purification resins. Mock drug formulations were used. Results will be presented demonstrating: quantitation range, spike and recovery analyses, sensitivity, versatile detection of Protein A ligands, inter- and intra-assay precision and improved workflow compared to traditional ELISA. The AMMP Protein A Assay on the ViBE Workstation performed similarly to sandwich ELISAs with comparable results across a range of Protein A ligands, greater sensitivity, excellent recovery in a broad range of sample concentrations, and with accurate and precise results from assay-to-assay, sensor-to-sensor, user-to-user. Additionally, comparable results between two established sample preparation methods allows for dramatic improvements in pre-assay sample prep resulting in significant workflow and hands-on-time advantages.