Mimic of green fluorescent protein (GFP) fluorophore for imaging RNA in living cells. Fluorescence activated by binding to Spinach2 or Broccoli aptamers. Exhibits peak excitation maxima of 482 nm and peak fluorescence emission of 505 nm when bound to Spinach2, enabling imaging with GFP filter cubes. Exhibits higher specific fluorescence and lower background fluorescence when bound to Spinach2 compared with Spinach2-DFHBI. Purity 98%. MW (observed): 320.21