ABSTRACT
Fluorescence microscopy along with engineered uorescent probes has become a very powerful and indispensable method for investigating the biology and pathology of cells and tissues (Lichtman and Conchello 2005). A variety of uorescent dyes and uorescent proteins have been developed for imaging various biological processes at the cellular and subcellular level. However, introduction of exogenous dyes and even least invasive uorescent proteins into cells and tissues has the risk of interfering with the cell biology and the activities of target biomolecules (e.g., proteins). In addition, these dyes are likely to be toxic and bind nonspecically; as a result, quantitative studies of cellular and molecular biophysics are undermined (Alford et al. 2009; Billinton and Knight 2001). Moreover, delivery of the uorescent probes into the cell is time consuming and oen dicult. e described limitations of exogenous labels highlight the importance and convenience of endogenous uorophores that cause cells and tissues to be naturally uorescent (autouorescent).
