Fig. 1Imaging translation of single mRNA molecules. (a) Schematic representation of the fluorescent labeling
of nascent polypeptides using the SunTag system and the labeling of mRNA using the PP7 system. A gene of
interest is fused to an array of SunTag peptides. When the mRNA is translated, scFv-GFP antibodies will bind
to the SunTag peptides that emerge from the ribosome, resulting in a bright fluorescent spot at the site of
translation and thus allowing real-time observation of protein synthesis. To visualize the mRNA, 24 PP7
Imaging Translation in Live Cells 387