Biotium offers high quality amine-reactive succinimidyl ester (SE, or NHS-Ester) dyes used to label proteins, oligonucleotides, and nucleic acids. We offer Cyanine 555 (Cy®3), Cyanine 647 (Cy®5), Cyanine 770 (Cy®5.5), and Cyanine 750 (Cy®7) as high quality succinimidyl esters. Also see our CF® Dye Succinimidyl Ester, available with more than 20 bright and photostable CF® Dyes.    Cyanine 555 is structurally identical to Cy®3 from GE Healthcare.    &lamba;Ex/&lamba;Em (water) = 555/565 nm  Dark red solid soluble in DMF and DMSO  Store at -20°C and protect from moisture and light  C41H56N4O10S2   MW: 829     Cy3, Cy5, Cy5.5, and Cy7 are registered trademarks of GE Healthcare.