A concise introduction to fundamental principles, this book presents the most important aspects of fluorescence spectroscopy, particularly as they are applied to biology, biochemistry, and biophysics. The author focuses on the essential aspects of fluorescence to encourage readers to design experiments, begin their own fluorescence measurements, and access the literature with greater comprehension. After a general definition of the field and an overview of the nature of light and absorption by biomolecules, the text covers instrumentation, emission spectra, excitation spectra, polarization, anisotropy, quenching, time-resolved methods, and FRET.