The Characterization of Biomolecular Interactions Using Fluorescence Fluctuation Techniques -- Characterization of Protein–Protein Interactions Using Atomic Force Microscopy -- Combined Solid-Phase Detection Techniques for Dissecting Multiprotein Interactions on Membranes -- Surface Plasmon Resonance Biosensing in the Study of Ternary Systems of Interacting Proteins -- Mass Spectrometry for Studying Protein Modifications and for Discovery of Protein Interactions -- H/2H Exchange Mass Spectrometry of Protein Complexes -- Elucidation of Protein–Protein and Protein–Ligand Interactions by NMR Spectroscopy -- Application of Isothermal Titration Calorimetry in Exploring the Extended Interface -- Solvent Mediated Protein–Protein Interactions -- Sedimentation Equilibrium Analytical Ultracentrifugation for Multicomponent Protein Interactions -- Structure Analysis of Macromolecular Complexes by Solution Small-Angle Scattering -- Fluorescence Detection of Proximity -- Steady-State and Time-Resolved Emission Anisotropy -- Analysis of Protein-DNA Equilibria by Native Gel Electrophoresis -- Electrospray Ionization Mass Spectrometry and the Study of Protein Complexes -- Sedimentation Velocity in the Study of Reversible Multiprotein Complexes.