HCP Analysis of a Small Drug-Protein in Process Sample

Among various evaluation methods to detect host-cell protein(HCP)impurities,2D-gel-based separation of drug samples followed by Western blotting with anti-HCP antibodies offers visual confirmation of immunodetected proteins. In addition to these visual results, ELISA-based assays provide a valuable high throughput tool to determine product purity in terms of total HCP content relative to the drug protein itself. Mass spectrometry-based orthogonal methods, such as GeLC MS/MSenablesidentificationof individual host cell proteins, and provides exact protein name, database entry number, amino acid sequence as well as theoretical and molecular weight for each identified HCP.

Here, we combine a high coverage platform immunoassay with highly sensitive GeLC-MS/MS for HCP analysis of both an in-process drug-protein and the corresponding E. colinull cell lysate. This combination of methods enables maximum coverage and information details on each HCP.