In spite of their relatively low fluorescence quantum yield, cyanine dyes such as Cy3, Cy5, or Cy7 are widely used in fluorescence-based applications due to their high extinction coefficients and excellent photon yields.
The known quantum yields for Cyanine dyes are available in table below:
| Name | MW | Quantum yield |
| Cy2 | 714 | 0.12 |
| Cy3 | 767 | 0.15 |
| Cy3.5 | 1102 | 0.15 |
| Cy5 | 792 | 0.27 |
| Cy5.5 | 1128 | 0.28 |
| Cy7 | 818 | 0.28 |