Fluorescence spectroscopy is an extremely powerful analytical tool that has been used in areas ranging from biology to physics. In this REPORT, we applications of fluores will present cence spectroscopy to bioanalytical systems, including DNA and RNA de- terminations, enzymatic methods, protein-ligand oassays, and interactions, fiber-optic-based fluoroimmun sensing. Space limitations preclude mention of other relevant areas (e.g., fluorescence detection in liquid chromatography). divided into the following sections: historical perspective, theory, instrumentation, advantages of fluorescence, applications, and the future.