Bioassays help drug developers determine the biological activity (potency) of their products, which has been a biopharmaceutical critical quality attribute (CQA) since long before that concept had a name. Because of their complex nature, bioassays are among of the most challenging experiments to perform reliably with dependably accurate results. Consistent assay performance requires a controlled environment and qualified reagents; skilled analysts who understand cell physiology, regulatory requirements, and the latest techniques; and assay protocols that are intelligently developed, characterized, and…