Questioning coverage values determined by 2D western blots: A critical study on the characterization of anti‐HCP ELISA reagents

Host cell proteins (HCPs) constitute a major class of process-related impurities, whose substantial clearance must be demonstrated by suitable analytical methods to warrant product quality and reduce potential safety risks for patients. In this regard, enzyme linked immunosorbent assays (ELISAs), which primarily rely on the quality of the HCP reference standard (immunogen) and HCP-specific polyclonal antibodies, are considered the gold standard...