Yes, DyLight™ dyes, DY547 and DY647, are alternatives to Cy3 and Cy5. The performance of these two dyes is similar to the equivalent Cy dyes and the absorption and emission spectra are virtually identical. A comparison of the emission or absorbance spectra of oligos shows that the spectra are virtually identical for Cy3 and DY547. Similarly, Cy5 and DY 647 are virtually identical. When oligos containing Dy547 were excited at 488 nm, the quantum yield (QY) was 12% greater than oligos containing Cy3. When oligos containing Dy647 were excited at 580 nm, the QY was 5% greater and the emission was blue-shifted by only 1 nm compared to Cy5.