Fluorescence relaxation spectroscopy in the analysis of macromolecular structure and motion

Fluorescence spectroscopy offers particularly sensitive tools for the investigation of physical properties of macromolecules in solution. Differences in molecular structure under varying experimental conditions are often reflected in quantum yield and lifetime of natural or synthetically inserted fluorescent probes. inserted fluorescent probes. Energy transfer between fluorescent groups at known places of a primary sequence can be used to measure distances between the label sites (Eisinger, 1976) as well as to investigate their relative motion, e.g. measurements of the kinetics of variations in the end to end distance of a polymer (E. Haas & I. Steinberg, personal communication).