Bio-Synthesis offers Alexa  568 fluorescent dye oligonucleotide labeling services. Alexa 568  is a orange fluorescent dye with excitation suitable for  the 568 nm laser line on the Ar-Kr mixed-gas laser. This dye is pH-insensitive over a wide molar range which permit stable signals for imaging and flow cytometry application. Characteristic features of the label are strong absorption, high fluorescence quantum yield, and high thermal and photo-stability. The dye allow detection of low-abundance biological structures with great sensitivity. Alexa Fluor® 568 is a substitute for Rhodamine Red, this molecules can be attached to oligo at multiple sites at high molar ratios without significant self-quenching, enabling brighter conjugates and more sensitive detection. 

  • Bright and photostable Lissamine rhodamine B substitute
  • Fluorescence output unmatched by any other spectrally similar dye
  • pH-insensitive fluorescence between pH 4 and 10

Alexa 568 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 Alexa 568 fluorescent dye oligonucleotide labeling services.

Product Information


Product Name:

Alexa 568 Oligo Labeling


Fluorescent dye Label, Rhodamine Red

Modification Code:


Chemical Formula:


Exact Mass:


Formula Weight:


Excitation (nm):

579 nm

Emission (nm):

603 nm

Extinction Coefficient, ε(λ):



Bio-Synthesis Inc. Oligo Structure


Dual HPLC required

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.