Recent progress in expanding the chemiluminescent toolbox for bioimaging.

Nowadays, the application of chemiluminescence imaging is no longer limited to the monitoring of slow biological phenomena such as circadian rhythms and in vivo tracking of cells. The expanded color palette of bright chemiluminescent protein and near-infrared-emitting luciferins have greatly improved the sensitivity of in vivo tracking of cells as well as enabling real-time cellular chemiluminescence imaging with high spatial resolution. Furthermore, functional chemiluminescent indicators based on the novel concept have been developed, providing more information related to physiological and pathological processes in living organisms. In this short review, we summarized the recent protein- and substrate-based approaches for tuning the emission wavelength, as well as for development of the functional indicators.