Fluorescence techniques are methods used to study materials that emit light after being excited by a specific wavelength. This process occurs when a substance absorbs photons and then re-emits them at a longer wavelength. Common applications include biological imaging, where researchers use fluorescent dyes to label cells or proteins, allowing for visualization under a fluorescence microscope. These techniques are widely used in various fields, including biochemistry, cell biology, and medical diagnostics. Instruments like fluorometers and confocal microscopes help detect and analyze the emitted light, providing valuable information about the structure and function of the studied samples.