Assay Packages: Lot Release and Stability Testing

Assay families that satisfy testing needs include:

• Physical testing

  Used to characterize the appearance of a mAb, for example through high accuracy (HIAC) particulate analysis, physical testing includes measurement of pH, osmolality and concentration. Packaging integrity is also assessed within physical testing protocol, for example using Karl Fischer moisture analysis or dye ingress to confirm closure integrity.

• Identification testing

  To confirm that your mAb product is what you think it is, it’s important to perform intact mass (IM) analysis, amino acid analysis, glycan profiling, and sequence mapping. Higher order structure (HOS) can also be evaluated.

• Product impurity testing

  The presence of impurities in your mAb product can present a serious risk and prevent regulatory approval. Techniques such as dynamic light scattering (DLS) and UHPLC ion exchange, used to check for size variants and charge variants respectively, provide essential data to support your clinical submission.

• Potency / binding testing

  The efficacy of your mAb hinges on its affinity for the target. Many different methods can be used to evaluate this, including Fc gamma receptor and C1q binding assays, specific measurement of target antigen affinity, and various cell-based assays such as antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-dependent cellular phagocytosis (ADCP) to qualify mAb potency.

• Microbiology testing

  To ensure your mAb’s quality and safety, several tests are essential to meet regulatory requirements. These include bioburden determination, bacterial endotoxin testing, and sterility testing, all of which are necessary to confirm product integrity.

• Process impurity / residual testing

  Impurities generated during the mAb production process can slow a mAb’s ability to move through the regulatory approval process. Rigorous monitoring is necessary to detect detergent or surfactant left behind during manufacturing, while the presence of residual protein and DNA also requires thorough evaluation.