METHOD AND APPARATUS FOR MEASURING FLUORESCENCE LIFETIME

摘要

A method of measuring fluorescence lifetime includes illuminating a sample containing at least one fluorophore with light to excite fluorescence and switching the intensity of the excitation light repeatedly between a first intensity I1 and a second intensity 12. Emitted light caused by fluorescence of the sample is detected and a detected light signal is generated. The detected light signal is switched repeatedly to divide it into first and second portions, and the amount of light detected during each of the first and second portions is measured to obtain a. first emitted light value S1 and a second emitted light value S2. The fluorescence lifetime is determined from the first and second emitted light values S1 and S2. The method may be used to identify labelled objects, wherein each object carries a label that contains a combination of fluorescent materials.