Research article published: Novel coverage method by ELISA-MS™

Research article on monitoring host cell protein coverage using ELISA-MS™

In this research article published in the July/August issue of Biotechnology Progress, our scientists present a novel coverage method combining ELISA-based immunocapture with protein identification by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Monitoring host cell proteins (HCPs) is one of the most important analytical requirements in the production of recombinant biopharmaceuticals to ensure product purity and patient safety.

Until now, Enzyme-linked immunosorbent assay (ELISA) has been the standard method for monitoring HCP clearance. However, in order to use it efficiently, it is important to validate that the critical reagent of an HCP ELISA, the HCP antibody, covers a broad spectrum of the HCPs potentially present in the purified drug substance.

Most coverage methods for assessing the ELISA's HCP antibody coverage are based on 2D-Western blot or immunoaffinity-purification combined with 2D gel electrophoresis. However, they have several limitations.

In the article, we present a novel coverage method that combines ELISA-based immunocapture with protein identification by liquid chromatography-tandem mass spectrometry(LC-MS/MS): ELISA-MS™. Thus it mimics the actual conditions of the ELISA antibodies.

We also show how ELISA-MS™ is used to accurately determine HCP coverage of an early process sample by three commercially available anti-Escherichia coli HCP antibodies, evading the limitations of current methods for coverage analysis and taking advantage of the benefits of MS analysis.

Get a list of individual HCPs covered by each HCP antibody

The results comprise a list of individual HCPs covered by each HCP antibody. The novel method shows high sensitivity, high reproducibility, and enables tight control of nonspecific binding through the inclusion of a species-specific isotype control antibody.

We propose that in the future, ELISA-MS™ will be a valuable supplement to existing coverage methods or even a replacement. ELISA-MS™ will increase the possibility of selecting the best HCP ELISA, thus improving HCP surveillance and resulting in a final HCP profile with the lowest achievable risk.