Analysis of NIST Antibody on the Agilent ProteoAnalyzer System

Significance of the Topic

Monoclonal antibodies (mAbs) are fundamental to modern biopharmaceuticals and demand precise characterization of purity and structural integrity. Electrophoretic methods under reduced and nonreduced conditions reveal fragment impurities, glycan occupancy, and aggregate content. The NISTmAb reference standard underpins method validation across the industry.

Objectives and Study Overview

This study compares the novel Agilent ProteoAnalyzer system to conventional single-capillary CE-SDS approaches using the NISTmAb. The aim is to assess performance metrics, purity determinations, and throughput enhancements offered by automated parallel analysis.

Methodology

NISTmAb was prepared at 2,000 ng/µL in PBS under reducing and nonreduced conditions. Samples were fluorescently labeled using the Agilent Protein Broad Range P240 kit and analyzed across multiple capillaries with optimized injection voltages. Lower and upper alignment markers enabled accurate quantitation and sizing.

Instrumentation Used

The Agilent ProteoAnalyzer system equipped with the ProteoAnalyzer Brand Range Kit and the Protein Broad Range P240 kit performed parallel capillary CE-SDS separations, supporting up to 12 simultaneous samples and unattended runs.

Main Results and Discussion

The ProteoAnalyzer resolved the monomer, light and heavy chains, interchain fragments (HC:LC, HC:HC) and high molecular weight aggregates. Under nonreduced conditions, monomeric purity was 98.18%, closely matching the 98.47% reference. Reduced analysis showed a thioether content of 0.40% versus 0.30% and glycan occupancy of 99.30% versus 99.39%. Resolution between nonglycosylated and glycosylated heavy chains exceeded specifications (R=1.60) with a 4.5% CV across capillaries.

Benefits and Practical Applications

The ProteoAnalyzer offers high-throughput, automated CE-SDS analysis with reliable purity metrics, facilitating QA/QC workflows in biopharmaceutical development and ensuring consistency with established standards.

Future Trends and Opportunities

Integration with mass spectrometry, expansion to a wider range of biotherapeutics, miniaturized lab‐on‐a‐chip formats, and AI-driven data analysis promise to further enhance throughput, resolution, and interpretative power in mAb characterization.

Conclusion

The Agilent ProteoAnalyzer provides robust, reproducible separations and accurate critical quality attribute measurements for NISTmAb, aligning well with reference data and supporting streamlined analytical workflows.

References

1. National Institute of Standards and Technology. Reference Material 8671: NISTmAb, Humanized IgG1κ Monoclonal Antibody.
2. Turner A. et al. Development of Orthogonal NISTmAb Size Heterogeneity Control Methods. Anal Bioanal Chem 410:2095–2110 (2018).
3. Schiel J. E. et al. The NISTmAb Reference Material 8671 Value Assignment, Homogeneity, and Stability. Anal Bioanal Chem 410:2127–2139 (2018).
4. Agilent Technologies. Agilent ProteoAnalyzer System Brochure, publication 5994-6716EN (2023).
5. Agilent Technologies. Protein Broad Range P240 Kit Quick Guide, publication D0031125 (2023).
6. Moritz B, Stracke JO. Assessment of Disulfide and Hinge Modifications in Monoclonal Antibodies. Electrophoresis 38(6):769–785 (2017).