As biocatalysis becomes increasingly important in active pharmaceutical ingredient (API) manufacturing, ensuring effective detection and quantification of residual proteins remains critical to product quality, safety and regulatory compliance. In a new white paper, Almac explores the use of SDS-PAGE (sodium dodecyl sulfate–polyacrylamide gel electrophoresis) as a robust and versatile approach for residual protein determination in complex API matrices.
The paper outlines how the technique can provide both qualitative and semi-quantitative analysis of residual host cell proteins and recombinant enzymes, offering an alternative to conventional absorption-based methods such as ELISA, Bradford and BCA assays, which can face limitations in specificity or sample compatibility.
Drawing on experimental development and QC verification studies, the white paper demonstrates how SDS-PAGE can support residual protein detection below 100 ppm, with findings suggesting levels below 25 ppm in tested samples. It also highlights the method’s robustness across challenging sample environments, including solvent-rich matrices, and its ability to reveal unknown impurities that may be missed by other analytical techniques.
According to the paper, the validated approach offers a cost-effective and informative tool for routine quality control, in-process enzyme monitoring and broader process optimisation in biocatalytic API production.
To read the full white paper, Use of SDS-PAGE for Residual Protein Determination, and explore the methodology and findings in detail, download it here.