-The coat protein from the bacteriophage MS2 binds a specific site on the viral mRNA genome. By fusing the genes for the Coat Protein (CP) and Green Fluorescent Protein (GFP), we can visualize the coat protein within cells.

-To image the localization of the mRNA for "Your Favorite Gene" (YFG), the binding site from the MS2 genome is appended to YFG. Coexpression of both components results in mRNA transcripts labeled with GFP.

-By fusing the 3' UTR from ASH1 to the MS2 CP binding site we are able to follow the localization of the ASH1 mRNA within the cell as fluorescent spots termed gRNA-ASH1.