Fluorescence spectroscopy has evolved rapidly in the past decade, driven by advances in time resolution, data analysis, and instrumentation. This book, "Topics in Fluorescence Spectroscopy," edited by Joseph R. Lakowicz, is a series that summarizes the vast literature on fluorescence spectroscopy. The third volume focuses on biochemical applications. The first three volumes are designed as an advanced text, covering recent techniques (Volume 1), principles of fluorescence (Volume 2), and biochemical applications (Volume 3). Additional volumes will be published as warranted by further advances in the field. The book includes contributions from experts in various areas of fluorescence. The first chapter discusses tyrosine fluorescence and phosphorescence from proteins and polypeptides, covering absorption properties, excited states, quenching mechanisms, and emission characteristics. The second chapter explores fluorescence and dynamics in proteins, including dynamics, decay and quenching, rotation of aromatic groups, molecular relaxation, and dynamics in protein globules. The third chapter examines tryptophan phosphorescence from proteins at room temperature, including phosphorescence formation, emission, quenching, and anisotropy. The fourth chapter discusses fluorescence studies of nucleic acids, focusing on rotational dynamics, steady-state studies, and dynamics of tRNAs. The fifth chapter covers fluorescence in membranes, including fluorescence lifetimes, anisotropy, energy transfer, quenching, and solvent relaxation. The sixth chapter explores fluorescence and immunodiagnostic methods, including various immunoassay formats and fluorescent probe design. The seventh chapter discusses total internal reflection fluorescence, including theory, emission near surfaces, and applications in microscopy. The eighth chapter covers microparticle fluorescence and energy transfer, discussing excitation and emission spectroscopy, energy transfer, and experimental results. The book provides a comprehensive overview of fluorescence spectroscopy and its applications in biochemical and biophysical research.Fluorescence spectroscopy has evolved rapidly in the past decade, driven by advances in time resolution, data analysis, and instrumentation. This book, "Topics in Fluorescence Spectroscopy," edited by Joseph R. Lakowicz, is a series that summarizes the vast literature on fluorescence spectroscopy. The third volume focuses on biochemical applications. The first three volumes are designed as an advanced text, covering recent techniques (Volume 1), principles of fluorescence (Volume 2), and biochemical applications (Volume 3). Additional volumes will be published as warranted by further advances in the field. The book includes contributions from experts in various areas of fluorescence. The first chapter discusses tyrosine fluorescence and phosphorescence from proteins and polypeptides, covering absorption properties, excited states, quenching mechanisms, and emission characteristics. The second chapter explores fluorescence and dynamics in proteins, including dynamics, decay and quenching, rotation of aromatic groups, molecular relaxation, and dynamics in protein globules. The third chapter examines tryptophan phosphorescence from proteins at room temperature, including phosphorescence formation, emission, quenching, and anisotropy. The fourth chapter discusses fluorescence studies of nucleic acids, focusing on rotational dynamics, steady-state studies, and dynamics of tRNAs. The fifth chapter covers fluorescence in membranes, including fluorescence lifetimes, anisotropy, energy transfer, quenching, and solvent relaxation. The sixth chapter explores fluorescence and immunodiagnostic methods, including various immunoassay formats and fluorescent probe design. The seventh chapter discusses total internal reflection fluorescence, including theory, emission near surfaces, and applications in microscopy. The eighth chapter covers microparticle fluorescence and energy transfer, discussing excitation and emission spectroscopy, energy transfer, and experimental results. The book provides a comprehensive overview of fluorescence spectroscopy and its applications in biochemical and biophysical research.