Rigid cyanine dye nucleic acid labels.

@article{Fegan2008RigidCD,
  title={Rigid cyanine dye nucleic acid labels.},
  author={Adrian Fegan and Pravin S. Shirude and Shankar Balasubramanian},
  journal={Chemical communications},
  year={2008},
  volume={17},
  pages={2004-6}
}
Cyanine dyes attached to DNA via a rigid linker show useful fluorescence and FRET properties without altering the stability of duplex DNA.