Simplify LC-MS Analysis of mAb Charge Variants - IonHance CX-MS pH Concentrates

Significance of the topic

Monoclonal antibody (mAb) charge variant profiling is essential in biopharmaceutical development and quality control, as subtle changes in glycosylation, C-terminal lysine processing, and other modifications can affect efficacy, stability, and immunogenicity.

Objectives and Study Overview

This study presents the development and application of IonHance CX-MS pH Concentrates (A and B) to streamline on-line LC-MS analysis of intact mAbs and mAb IdeS digests. The aim is to reduce adduct formation, minimize ion suppression and supercharging, and deliver high-fidelity mass spectra for detailed charge variant characterization.

Methodology and Instrumentation

The workflow employs:

• BioResolve SCX mAb columns for high-resolution separation of charge variants.
• IonHance CX-MS pH Concentrates A (acidic) and B (basic) formulated for MS compatibility.
• MS-grade water added to 10× concentrates in certified LDPE bottles to prepare mobile phases.
• High-resolution mass spectrometer interfaced on-line with the SCX column.

Main Results and Discussion

Use of IonHance CX-MS pH buffers led to significantly cleaner spectra with reduced non-desired adduct peaks and mitigated supercharging effects. Key observations include:

• Distinct deconvoluted profiles of intact mAbs, resolving glycoforms (e.g., G0F/G1F, G1F/G1F) and C-terminal lysine variants.
• Reproducible separation of acidic and basic charge variants without peak broadening.
• Enhanced detection of IdeS-generated fragments (F(ab')2 and (Fc/2)2) with clear assignment of post-translational modifications.

Benefits and Practical Applications

The IonHance buffer system offers:

• Improved spectral clarity for confident assignment of glycoforms and charge variants.
• Reduced method development time by using pre-formulated, MS-compatible buffers.
• Compatibility with existing SCX mAb columns and standard LC-MS platforms in QC and R&D laboratories.

Future Trends and Applications

Emerging directions include integration of these buffers into automated QC workflows, adaptation to native MS for higher-order structure analysis, and coupling with AI-driven data analysis to accelerate biopharmaceutical characterization.

Conclusion

IonHance CX-MS pH Concentrates simplify and enhance LC-MS workflows for mAb charge variant analysis, delivering reproducible, high-quality spectra that support rigorous biotherapeutic development and quality assurance.