An introduction to fluorescence imaging techniques geared towards biosensor applications.

After providing a brief overview of the basics of fluorescence and FRET, this chapter discusses the most commonly used methods to record FRET. Emphasis is on microscopy methods that are widely used for biosensor imaging. We cover choice of instruments, describe various ways to detect FRET based on intensity as well as on donor lifetime, and provide some guidelines to match particular recording methods with specific scientific experiments. We end with an extensive discussion on further practical considerations that may greatly affect the success of the experiments.