Potency is a critical quality attribute of a biological product and is often determined by a biological assay (also called bioassay or biopotency assay). Specifically, potency is the biological activity or capacity of a product directly linked to its clinical efficacy. Potency tests are performed as part of product release, comparability studies, and stability testing. Nonbiological methods — which measure a product’s molecular or biochemical characteristics (e.g., ligand-binding assay) — have gained interest as replacements for often troublesome bioassays. Even…