text: Light at the end of the tunnel.
  Turn the light on: The synthesis, folding and maturation kinetics of individual green fluorescent protein (GFP) molecules have been studied using a cell-free transcription-translation system and single-molecule fluorescence. Ribosomes, which were labeled with a red fluorophore and tethered to a glass surface, were used to synthesize GFP Emerald molecules that become fluorescent after maturation.