====== Functional Assay ====== A **functional assay** is a laboratory test designed to evaluate whether a biological component (such as a gene, protein, or cell) performs its expected **biological function** under defined experimental conditions. ===== Definition ===== A functional assay is used to assess the **activity, behavior, or performance** of a biological molecule or system, often to determine its role in health or disease. > It measures what the component **does**, not just what it **is**. ===== Common Applications ===== * Determining the effect of **genetic variants** (e.g. VUS) * Testing **enzyme activity** * Evaluating **drug responses** in vitro * Measuring **cell proliferation**, apoptosis, or migration * Assessing **receptor signaling** capacity ===== Examples ===== ^ Target ^ What It Tests ^ Example ^ | Enzyme | Catalytic activity | ATPase assay for energy metabolism | | Receptor | Signal transduction | G-protein coupled receptor activation | | Gene variant | Transcriptional regulation | Luciferase reporter assay | | Cell | Proliferation/apoptosis/migration | MTT assay, scratch wound healing test | ===== Importance ===== Functional assays are essential in: * Interpreting the clinical relevance of **mutations** * Validating **therapeutic targets** * Exploring **mechanisms of disease** * Confirming **biological activity** of recombinant or engineered molecules ===== Related Terms ===== * [[biological assay]] * [[luciferase reporter assay]] * [[in vitro assay]] * [[variant of uncertain significance]]