Size-Exclusion Chromatography (SEC)

Size-Exclusion Chromatography (SEC) is an analytical separation technique that resolves molecules based on hydrodynamic size, using porous stationary phases that delay smaller molecules while allowing larger molecules to elute earlier. SEC is widely used for evaluating protein aggregation, fragmentation, and overall molecular size distribution.

In biopharmaceutical quality control, SEC serves as a key method for monitoring product purity and stability, particularly for monoclonal antibodies and other biologics prone to aggregation. SEC profiles help quantify high-molecular-weight species linked to immunogenicity risk and low-molecular-weight fragments associated with degradation. Method robustness requires careful control of column selection, mobile phase composition, flow rate, and sample load to ensure reliable comparability across batches and throughout shelf life. Regulatory submissions include SEC data as part of critical quality attribute characterisation, with specifications limiting aggregates and fragments. As therapeutic modalities become more complex and regulatory expectations for detailed characterisation intensify, SEC continues serving as a fundamental analytical tool enabling consistent product quality assessment and stability programme support across the biopharmaceutical industry.