Beyond Detection: Evaluating Mass Spectrometry Methods For Robust Host Cell Protein Quantification

While traditional ELISA remains the standard for total host cell protein (HCP) quantification, mass spectrometry has evolved into a critical orthogonal tool for deeper process insights. The introduction of USP Chapter 1132.1 in 2025 provides a much-needed framework for standardizing these complex analytical methods, offering clear guidance on instrument selection and data reporting. By implementing these strategies, manufacturers can move beyond basic detection to identify specific persistent contaminants that might co-purify with a drug substance.

Different acquisition strategies, such as data-independent acquisition for broad discovery and parallel reaction monitoring for targeted, absolute quantification, allow teams to tailor their approach based on the lifecycle of the product. Integrating these sophisticated MS methods early in development helps mitigate long-term risks, ensuring a comprehensive understanding of the HCP profile. This strategic alignment with new regulatory expectations streamlines the path to clinical and commercial success.