A potency test, known as a quantitative test, is designed to measure and determine the biological activity of the given live biotherapeutic products. The potency of live biotherapeutic products is generally a measure of viable cells per unit or dose, i.e., colony-forming units (CFUs), depending on the specific product strains and knowledge of the mechanisms of action. Biological activity or potency is a critical quality attribute; therefore, potency testing is an essential component of quality control for live biotherapeutic products.