Bio-Synthesis offers ATTO 655 fluorescent dye oligonucleotide labeling at any position of an oligonucleotide. The fluorescence of ATTO655  is excited most efficiently in the range 640-660 nm. A suitable excitation source is the 647 nm line of the Krypton-Ion laser or a diode-laser emitting at 650 nm. They dye can be use as an alternative dye for Cy5, Alexa flour 647 or DY649

  • Replacement dye for Cy5, Alexa 647, DY649
  • High fluorescence yield
  • Excellent thermal and photo-stability
  • Excellent ozone resistance
  • Fluorescence quenching by guanine, tryptophan
  • Very hydrophilic

ATTO655 Wavelength

Characteristic features of the ATTO-655 label are strong absorption, high fluorescence quantum yield, high thermal and photo-stability,  exceptionally high stability towards atmospheric ozone, and very good water solubility. Thus ATTO 655 is highly suitable for single-molecule detection applications and high-resolution microscopy such as PALM, dSTORM, STED etc. Additionally the dye highly qualifies to be applied in flow cytometry (FACS), fluorescence in-situ hybridization (FISH) and many more.

ATTO 655 dye can be incorporated at any position within an Oligonucleotide. A primary amine modified oligonucleotide is used to covalently attach with dye via NHS conjugation chemistry; other cross-linking chemistries are also available depending on particular project specifications. Dual HPLC purification is used to remove failure sequences during first HPLC purification,  after labeling, the second HPLC is performed to remove unlabeled oligonucleotides and excessive dye in order to obtain a full length labeled oligonucleotide.

Contact us for ATTO 655 fluorescent dye oligonucleotide labeling services.

Product Information


Product Name:

ATTO 655 Fluorescent Dye Oligonucleotide Labeling


Fluorescent dye Label, Cy5 Alternative

Modification Code:


Absorption λmax:


Excitation (nm):


Emission (nm):


Extinction Coefficient, ε(λ):


Fluorescence QuantumYield, η:


Fluorescence Lifetime, τ:



dual HPLC

Delivery Format:


Shipping Conditions:

Room Temperature

Storage Conditions:

-20°C To -70°C
Oligonucleotides are stable in solution at 4°C for up to 2 weeks. Properly reconstituted material stored at -20°C should be stable for at least 6 months. Dried DNA (when kept at -20°C) in a nuclease-free environment should be stable for years.