Vector Labs is closed to observe Juneteenth (US Holiday) on Wednesday, June 19th.
We will be back in the office on Thursday. We will respond to emails upon our return. Have a wonderful day.

5-ROX NHS Ester (FP-1274)



5-Carboxy-X-rhodamine N-succinimidyl ester (5-ROX NHS Ester) is used as an amine coupling reagent to form 5-carboxy-X-rhodamine (ROX) derivatized compounds such as proteins, nucleic acids and drugs that may be analyzed by fluorescence resonance energy transfer (FRET) and fluorescence quenching applications. Labeling reagent for preparation of charge-modified dye-labeled ddNTPs to “direct-load” DNA sequencing. Conjugates of this dye have longer-wavelength spectra than the spectra of Lisaamine™ rhodamine B conjugates, but somewhat shorter-wavelength spectra than those of Texas Red™ conjugates.


Unit Size25 mg, 100 mg, 1000 mg
ReactivityPrimary amines
Abs/Em Maxima582/606 nm
Extinction coefficient93,000 cm-1M-1
SolubilityDMSO, DMF, MeOH
Spectrally similar dyesAlexa Fluor® 568, TAMRA, CF™ 568
Molecular weight631.69
Storage Conditions-20°C.
Shipping ConditionsAmbient temperature

Abs/Em Spectra

Rox Full Rox full

Protein Labeling Calculator


Applicable patents and legal notices are available at legal notices.

How do I Request a Quote?

To request a quote for products:

  1.  Log in to
  2.  Add the items you wish to quote to the cart;
  3.  View your cart;
  4.  Click on the “Request a Quote” button found below the items in your cart;
  5.  Download your quote