Antibody Purification in Bioprocessing

The affinity capture step is the primary operation in a downstream purification train. In a single pass, it can reduce the bulk of process-related impurities, including host cell proteins (HCP), cell debris, and DNA. Protein A chromatography resins remain a widely adopted choice for mAb capture. Thermo Fisher Scientific offers an extensive affinity capture portfolio: the Thermo Scientific MabCaptureC Affinity Matrix for Protein A-based mAb capture, and CaptureSelect affinity resins for formats requiring other subdomain-specific selectivity.
 

Protein A chromatography for mAb capture

The Thermo Scientific MabCaptureC Affinity Matrix is a high-performance Protein A resin designed for process-scale monoclonal antibody and mAb biosimilar purification. Designed to offer cost-savings, with a dynamic binding capacity (DBC) greater than 50 g/L at a residence time of 4.8 minutes, it can support cost-effective, high-throughput capture operations.

CaptureSelect affinity resins for bispecifics, antibody fragments, and Fc-fusion proteins

CaptureSelect affinity resins are based on single-domain VHH antibody fragment-derived ligands that bind antibody subdomains with high specificity. Their compact structure allows access to epitopes that larger Protein A ligands cannot reach, enabling subdomain-selective capture of complex formats.

CaptureSelect subdomain-specific resins, including CaptureSelect CH1-XL, CaptureSelect KappaXP, CaptureSelect LambdaXP, CaptureSelect FcXP, and POROS CaptureSelect FcXP, are designed to support the purification of bispecific antibodies, antibody fragments, F(ab')2, Fc-fusion proteins, and advanced format biosimilars. CaptureSelect CH1-XL targets the CH1 domain and does not co-purify free light chains, enabling platform purification of human IgG and antibody fragments with elution at a mild pH 4–4.5.

Following affinity capture, additional antibody purification techniques are used to reduce residual process- and product-related impurities before the drug substance advances to formulation. Thermo Scientific POROS chromatography resins are designed for intermediate and final polishing in antibody purification workflows. Their 50 µm bead size and poly(styrene-divinylbenzene) backbone support high-capacity, high-resolution, and flow rate-independent performance. Available chemistries include ion exchange chromatography (IEX), hydrophobic interaction (HIC), and mixed-mode (MMC) to address a broad range of polishing requirements across different antibody formats and process conditions.

 

IEX chromatography for mAb polishing

POROS cation exchange resins, such as POROS XS and POROS 50 HS, support mAb polishing in bind/elute or flow-through mode. These resins have wide pH compatibility and high binding capacity across varied process conditions.

POROS anion exchange resins, including POROS XQ, POROS 50 HQ, POROS 50 PI, and POROS 50 D, are designed for impurity reduction and can be operated in flow-through mode to simplify process development.

Hydrophobic interaction and mixed-mode resin

POROS HIC resins, Ethyl, Benzyl, and Benzyl Ultra, are designed for aggregate reduction and product-related impurity clearance in the purification of antibodies. Mixed-mode resin, such as POROS Caprylate Mixed-Mode Cation Exchange Chromatography Resin, is a flow-through polishing option designed for improved process economics and broader operating space, supporting efficient aggregate clearance with minimal product loss.