Fluorescent labeling is a technique used in biological research to track and visualize specific molecules or structures within cells. This method involves attaching a fluorescent dye or probe to a target molecule, allowing it to emit light of a specific wavelength when exposed to certain wavelengths of light. This enables researchers to observe the movement, localization, and interactions of molecules in real-time within living cells or tissues. Fluorescent labeling has numerous applications in various fields such as cell biology, neuroscience, and drug discovery, providing valuable insights into cellular processes and protein dynamics.