Optimizing Antibody Development: The Strategic Integration of Affinity Chromatography

Pharma analytics Article | Protein Analytics Optimizing Antibody Development: The Strategic Integration of Affinity Chromatography Introduction Biopharmaceutical manufacturing requires a strong and reliable bridge between a promising early-stage molecule and a market-ready drug product. The strength of this bridge depends on the quality and reproducibility of analytical data. In modern purification, affinity chromatography is no longer merely a capture step; it is a primary driver of bioprocess performance.1 Effective antibody development benefits from early-stage consideration of analytical needs. Implementing robust and highly specific affinity methods during the earliest stages of development streamlines the journey through clinical trials and complex regulatory filings. As antibody formats evolve from standard structures to include complex novel modalities like bispecifics and antibody–drug conjugates (ADCs), traditional platform methods like Protein A are being supplemented or replaced by more versatile and engineered ligand technologies. By integrating these specific methods into a unified analytical paradigm, development teams can achieve the high level of reproducibility, speed, and long-term confidence required to navigate the inherent complexities of modern bioproduction. This approach helps ensure that data collected in small-scale laboratories remains relevant and valid as projects scale to massive production volumes. This article explores how these advanced analytical strategies, including engineered ligands and high-throughput workflows, can support more efficient and robust antibody development from early-stage research to late-stage production. Watch the complete Teach Me in 10 episode with Dr. Kelly Flook here. Kelly Flook, PhD, Senior Product Manager, BioProduction Group Kelly Flook, PhD, is a Senior Manager within the bioproduction product management team at Thermo Fisher Scientific, where she leads strategy and development for advanced analytical technologies supporting bioprocessing workflows. With more than 20 years of experience in chromatography and bioseparation, Kelly specializes in scalable solutions for complex biologics, including monoclonal antibody-based therapeutics and next-generation vaccines.The basics of affinity chromatography The process behind affinity chromatography is elegant and simple, yet capable of achieving high purity in a single step by following a framework of loading, flushing, and eluting (Figure 1). The core mechanism relies on the high biological specificity of a target molecule for an immobilized ligand on a stationary phase within a column. Unlike other forms of chromatography that rely on physical properties like size or net charge, affinity chromatography mimics natural biological interactions, such as the relationship between an antigen and a target molecule. Crude samples are often incredibly dirty mixtures containing thousands of different host cell proteins, lipids, and cellular debris. However, when a sample is loaded onto the column, only the target molecule binds to the ligands and is held firmly by the stationary phase; all other impurities simply flow through the system and are discarded. Then, by switching the mobile phase or eluent to a different pH, for example, the target analyte is selectively released. As only the target is captured and subsequently released, the resulting data provides a highly accurate reflection of the actual titer and bioreactor yield. This helps provide a clean and reliable baseline for every subsequent analytical step in the process and reduces the noise that often affects other forms of protein analysis. Integrating affinity-based methods for data confidence While affinity chromatography is a powerful standalone tool, integrating it into a unified analytical suite allows a holistic approach toward molecular characterization. High-resolution techniques, such as size exclusion chromatography (SEC) and ion exchange chromatography (IEX), are used to characterize proteins. SEC can measure aggregation and fragmentation, while IEX profiles charge variants that may impact pharmacodynamics. These methods can be combined with affinity-based quantitation to build a comprehensive picture of target biomolecules.2,3 Integration also extends to impurity analysis, such as measuring residual DNA via quantitative polymerase chain reaction (qPCR) methods. When these diverse data streams are unified, they allow reproducible analysis, early-stage decision making, and cross-site reproducibility, saving time and money in process development and bioprocessing. Addressing challenges of novel modalities The biopharmaceutical industry is rapidly moving beyond traditional monoclonal antibodies toward much more complex molecular formats, including ADCs, bispecifics, Fc-fusion proteins, and Fab fragments. ADCs link a cytotoxic drug to an antibody, while bispecific antibodies can bind to two different targets simultaneously.4 Fc-fusion proteins combine a therapeutic protein with the Fc region of an antibody to improve stability and extend half-life, whereas Fab fragments consist only of the antigen-binding region, offering smaller size and improved tissue penetration.5,6 Figure 1. The load, flush, elute workflow of affinity chromatography. Load Flush Elute Sample injected onto column containing target molecule and impurities Target binds to the affinity resin in the column and impurities flow through Target is then eluted using a buffer change, typically, pH or salt Immobilized ligand Complex Impurities Purified target Feedstock containing impurities 2One of the most widely adopted affinity approaches is Protein A chromatography, which offers highly selective binding to specific parts of the Fc region of an antibody.1 While most traditional antibody-based products contain this region, as researchers re-engineer molecules to enhance therapeutic design, it is often altered or entirely removed (Figure 2). When the primary binding site is lost, Protein A is no longer a universal platform for all molecules. This shift forces development teams to look toward alternative domains, such as the light chain, to find new binding sites that remain intact. Consequently, a diverse suite of specialized ligands has been developed to preserve the platform benefits of speed and simplicity, even as molecular structures become increasingly complex. The CaptureSelect Ligands from Thermo Fisher Scientific exemplify this approach, offering selective binding to regions beyond the Fc domain, that include light chains and Fab fragments. These ligands help support both purification and analytical applications, and are available in multiple formats. Formats include purification bioprocessing resins, packed column formats suitable for HPLC, and conjugated ligands to support analytical techniques such as ELISA, SPR, and BLI. Such diverse formats allow researchers to tailor their approach based on both the structure of the molecule and the specific analytical objectives. Supporting high-throughput workflows and process development In addition to targeting different antibody regions for analysis, today’s processes also rely on high-capacity, fast, and robust columns to keep pace with high-throughput workflows, real-time decision making, and cross-site reproducibility. Labs today can generate hundreds of samples every week. Without reliable solutions, analysis becomes a bottleneck that affects the entire drug development pipeline. Efficiency in upstream process development is critical, such as understanding peak protein concentration during the bioreactor phase. Rapid affinity analysis provides the quick feedback loop necessary to optimize these bioreactor processes in real time. Accurate titer from dirty samples like harvest cell culture fluid (HCCF) requires robust columns that maintain linearity over a wide concentration range. Downstream robustness is equally important because the purification monitoring process generates an enormous volume of samples that must be processed quickly. As columns handle a variety of sample types from clarified HCCF to high salt samples from polishing steps, they must be fast, mechanically stable, and chemically tolerant so they can be cleaned and reused many times without frequent clogging or chemical degradation. High-speed analysis allows teams to identify success or failure rates immediately rather than waiting days for results, reducing downtime and helping ensure that expensive manufacturing resources are only allocated to the most promising drug candidates. Fab F(ab’)2 Fab Bi-specific IgG containing kappa or lambda light chain IgG Fc-fusion protein CaptureSelect CH1-XL MabCaptureC MabCaptureC V H C H1 C H2 C H3 V L C L CaptureSelect FcXP CaptureSelect KappaXP CaptureSelect LambdaXP Figure 2. CaptureSelect affinity resins for analysis of diverse antibody formats, including Fabs, bispecifics, and Fc-fusion proteins. 3Adapting affinity platforms for emerging modalities The scope of affinity chromatography is continuing to expand beyond the traditional antibody space into a much broader range of therapeutic modalities. As molecules become increasingly complex, the need for robust and rapid analytical approaches is driving the adoption of affinity-based solutions, particularly in the context of at-line or in-line process analytical technology. These methods allow faster and more informed decision-making during manufacturing. This expansion is not limited to antibodies but extends to a wide range of recombinant and therapeutic proteins, many of which currently lack established affinity solutions due to the highly specific nature of ligand–target interactions. As a result, there is a significant opportunity for growth within the affinity space as new ligands and technologies are developed to address these unmet needs. At the same time, the increasing complexity of molecules further highlights the value of integrating robust, high-speed analytical tools directly into production processes. This shift enables continuous monitoring and supports more efficient and adaptable manufacturing, reinforcing the role of affinity chromatography as a key technology in the future of bioprocessing. References 1. Łącki KM, Riske FJ. Affinity chromatography: an enabling technology for large-scale bioprocessing. Biotechnol J. 2019;15(1):e1800397. doi: 10.1002/biot.201800397 2. Lambiase G, Inman SE, Muroni M, Lindo V, Dickman MJ, James DC. Highthroughput multiplex analysis of mAb aggregates and charge variants by automated two-dimensional size exclusion–cation exchange chromatography coupled to mass spectrometry. J Chromatogr A. 2022;1670:462944. doi: 10.1016/j. chroma.2022.462944 3. Imiołek M, Fekete S, Rudaz S, Guillarme D. Ion exchange chromatography of biotherapeutics: fundamental principles and advanced approaches. J Chromatogr A. 2025;1742:465672. doi: 10.1016/j.chroma.2025.465672 4. Shim H. Bispecific antibodies and antibody–drug conjugates for cancer therapy: technological considerations. Biomolecules. 2020;10(3):360. doi: 10.3390/ biom10030360 5. Rath T, Baker K, Dumont JA, et al. Fc-fusion proteins and FcRn: structural insights for longer-lasting and more effective therapeutics. Crit Rev Biotechnol. 2015;35(2):235–254. doi: 10.3109/07388551.2013.834293 6. Chen H, Chen J-S, Paerhati P, et al. Strategies and applications of antigen-binding fragment (Fab) production in Escherichia coli. Pharm Fronts. 2021;3(2):e39–e49. doi: 10.1055/s-0041-1735145 For research and development use only in support of FDA-regulated end uses. Not for diagnostic use or direct administration to humans or animals © 2026 Thermo Fisher Scientific Inc. All rights reserved. All trademarks are the property of Thermo Fisher Scientific and its subsidiaries unless otherwise specified. TaqMan is a trademark of Roche Molecular Systems, Inc., used under permission and license. CaptureSelect resins: For research and development use and further manufacturing in support of FDA-regulated end uses. Not for diagnostic use or direct administration to humans or animals. POROS resins: For research and development use only in support of FDA-regulated end uses. Not for diagnostic use or direct administration to humans or animals WTP-14377551 Learn more at thermofisher.com/antibody-derived-therapeutics