A bioassay is a scientific method used to measure the effects of a substance on living organisms. This technique helps researchers determine the potency and effectiveness of drugs, toxins, or other chemicals by observing their impact on biological systems, such as cells, tissues, or whole organisms. Bioassays can be performed in various ways, including using cell cultures or animal models. The results provide valuable information for fields like pharmacology, environmental science, and toxicology, helping to ensure safety and efficacy in new treatments or to assess the impact of pollutants on ecosystems.