Author Archives: Anthony R. Newcombe

Revisiting Protein A Chromatography

Due to the molecular complexity of monoclonal antibodies (MAbs) and potential impurities in cell culture media before purification (host-cell proteins, DNA, media components) (1), subsequent downstream operations must consistently and reproducibly purify products to ensure safety and efficacy. The latest member of GE Healthcare’s MabSelect family is called MabSelect SuRe LX (2). As Table 1 shows, it has been developed using the same highly cross-linked agarose base matrix and protein A ligand as for other MAb affinity resins (Table 1).…

Validation of Intermediate Hold Times

    Because of the molecular complexity and relative fragility of biotherapeutics, validated intermediate hold times are critical for their commercial manufacture. Manufacturers typically conduct studies to define acceptable hold times for process intermediates to determine acceptable hold times for in-process production samples. A validation study defines maximum allowable hold times for all intermediate process stages based on product-specific data obtained during a hold study. A systematic risk assessment can determine which intermediate hold points should be validated (1). Hold…