Biological assays are experimental procedures used to measure the effects of a substance on a living organism. These assays are commonly used in fields such as pharmacology, toxicology, and environmental science to evaluate the potency, efficacy, or toxicity of a drug, chemical, or pollutant. Biological assays can include a wide range of techniques, such as cell-based assays, enzyme assays, and animal studies, to assess biological activity and function. These assays provide valuable information for drug discovery, safety assessment, and understanding the mechanisms of action of bioactive compounds.