Recent progress in luminescent proteins development.

Bioimaging requires not only high sensitivity but also minimal invasiveness. Bioimaging using luminescent proteins is potentially free from problems such as photo-induced damage or an undesirable physical reaction to the sample, which are often caused by illumination with an external light required in fluorescence imaging. The recent development of several luminescent proteins and substrates have greatly improved the brightness of luminescence imaging, facilitating its application by many researchers. In this short review, we summarize recent advances in development of luminescent proteins, substrates, and indicators.