Bio-Synthesis offers ATTO 425 fluorescent dye oligonucleotide labeling services. ATTO 425 is a fluorescent label with a coumarin structure. Characteristic features of the label are high fluorescence quantum yield, large Stokes-shift, high photostability, and low molecular weight.

ATTO 425 is moderately hydrophilic. Its fluorescence can be excited efficiently in the range 405-455 nm and this dye can be use to replace Alexa Flour 430. This compound requires a primary amine for conjugation onto an oligonucleotide via NHS ester conjugation chemistry. Click reaction is also available. Dual HPLC is highly recommended.

ATTO425 wavelength

ATTO 425 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 425 fluorescent dye oligonucleotide labeling services.

Product Information


Product Name:

ATTO 425 Fluorescent Dye Oligonucleotide Labeling


Fluorescent dye Label, Alexa Fluor 430 Alternative

Modification Code:


Absorption λmax:

439 nm

Extinction Coefficient, ε(λ):


Fluorescence Maximum, λfl:

484 nm

Fluorescence QuantumYield, η:


Fluorescence Lifetime, τ:

3.6 ns


Bio-Synthesis Inc. Oligo Structure


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.