What can fluorescence lifetime measurements be used for?
Fluorescence lifetime can be used to detect most common quenching processes, and often allows a correction to be applied to improve quantitation of fluorescent labels. Fluorescence INTENSITY depends on the amount of fluorescent label, on the intensity of the excitation light source and on the presence or absence of quenching processes. Fluorescence LIFETIME on the other hand is normally not dependent on the amount of fluorescent label present (unless some concentration-dependent self-quenching is involved), and does not depend on the intensity of exciting light. Thus, measurement of both lifetime and intensity of fluorescence can often be combined to detect most types of important quenching processes. In some cases fluorescence lifetime data can be used in conjunction with other techniques to reduce the ambiguity of results. Polarisation imaging is an example of a technique where measurement of fluorescence lifetime variations within a sample can help to improve quantification. Fluores
