Lifetime-resolved fluorescence imaging

Fluorescence lifetime imaging is a relatively new technique for acquiring directly the nanosecond temporal characteristics of the fluorescence emission of a spatially extended object, and for capturing the dynamic features at every pixel of an image simultaneously. In general, the applications of fluorescence lifetime imaging have been mainly in the microscope, but other diverse imaging situations can benefit from the technology. Our instrument employs periodically modulated excitation light, synchronous modulation of the amplification stages of a microchannel plate intensifier, and subsequent digital recording of the image with a charge-coupled device camera. The digitized images can be subsequently analyzed with a variety of different ways. A short description of the lifetime resolved fluorescence imaging instrumentation is given together with typical applications depicting lifetime spatial distributions, multiple lifetime analysis, statistical analysis of the image data, and suppression or enhancement of particular fluorescent species.