Bio-Synthesis offer Texas Red  fluorescent dye oligonucleotide labeling services. Texas Red, sulforhodamine 101 acid chloride, is a red-purple fluorescent dye can be label at any position within an oligonucleotide. The fluorescence conjugates has peak excitation wavelength in 595 nm and emission wavelength in 615 nm. Oligo conjugates emit at a longer wavelength than do either tetramethylrhodamine or Lissamine rhodamine B, and are among the most commonly used long-wavelength "third labels" in fluorescence microscopy and flow cytometry or as real-time PCR applications as a reporter moiety in TaqMan probes 1,  Scorpion primers2  and Molecular Beacons3. For such probes, Texas Red is most commonly paired with the dark quencher BHQ-2, as the two have excellent spectral overlap. Texas Red labeled oligonucleotide are been used in hybridication probes in a variety of in vivo and in vitro research or diagnostic applications, as well as for structure-function studies of DNA, RNA, and protein-oligonucleotide complexes.

Characteristic feature of Texas Red are:

  • Good spectral separation from green fluorophore
  • Absorbance max: 589
  • Emission max: 615
  • Single or mix isomeric form
  • Application: fluorescence microscopy, flow cytometry, real-time PCR

Texas Red 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 highly recommended.

Contact us for Texas Red fluorescent dye oligonucleotide labeling services.

Product Information


Product Name:

Texas Red Oligo Labeling


Fluorescent dye Label, Near infrared Long Wavelength Dyes

Modification Code:


Chemical Formula:


Exact Mass:


Formula Weight:


Excitation (nm):


Emission (nm):



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.



  1. Livak, K.J., Flood, S.J.A., Marmaro, J., Giusti, W., Deetz, K. Oligonucleotides with fluorescent dyes at opposite ends provide a quenched probe system useful for detecting PCR product and nucleic acid hybridization.PCR Methods Appl. (1995), 4: 1-6.
  2. Thelwell, N., Millington, S., Solinas, A., Booth, J., Brown, T. Mode of action and application of Scorpion primers to mutation detection. Nucleic Acids Res. (2000), 28: 3752-3761.
  3. Tyagi, S., Kramer, F.R. Molecular beacons: probes that fluoresce upon hybridization. Nat. Biotechnol. (1996), 14: 303-308. - Texas Red fluorescent dye