The chemical name of Rox (Figure 1) is 6-Carboxyl-X-Rhodamine. It is an inert fluorescent dye which is normally used as a reference dye to normalize the fluorescence signal arising from fluorescent probes in real-time PCR applications, as its fluorescence signal is not affected by reaction in PCR.
Rox represents an excellent alternative to PET®, due to their similar spectral properties.
![](https://www.metabion.com/uploads/5-Rox-Ester.png.pagespeed.ce.0oA_1ewX81.png)
Figure 1. Structure of 5'-Rox (R = sequence).
metabion offers the Rox modification in its DNA and RNA portfolio: