Shining a light on the dark secrets of the cell: synthetic proteins for better fluorescence imaging

The discovery of intrinsically fluorescent proteins revolutionized our ability to visualize proteins within living cells. Since that original observation, a plethora of fluorescent proteins with varied colour and brightness have been obtained. For a number of imaging purposes, however, synthetic biology approaches have been required to create new labelling methodologies. Here, we describe the protein engineering technologies that underlie some of those key designs and show how they have been used to great effect in different cell types.