Emission microspectroscopy is a sensitive technique with excitation and emission ranging from the ultraviolet, visible and NIR regions.  As such, it has numerous biomedical, biotechnological and agricultural applications. There are several powerful, highly specific and sensitive fluorescence techniques that are currently in use, or still being developed; among the former are FLIM, FRAP, FRET and FLIM-FRET; among the latter are NIR fluorescence and probe-sensitivity enhanced NIR fluorescence microspectroscopy and nanospectroscopy techniques (see "Further reading" section).  Fluorescence emission microspectroscopy and imaging are also commonly used to locate protein crystals in solution, for the characterization of metamaterials and biotechnology devices.