AAT Bioquest

6-ROX is predominately used as a reference dye for performing PCR detections, however, 6-ROX is very unstable compared to other rhodamine dyes. What is a better dye replacement?

Posted July 15, 2020


6-ROXtra™ has greatly improved stability and water solubility. 6-ROXtra™ has almost identical spectral properties to those of 6-ROX. This 6-ROXtra™ dye is 25 µM solution in 20 mM Tris (pH 8.4), 0.1 mM EDTA and 0.01% Tween® 20. 6-ROXtra™ dye is stable at room temperature for a few weeks, making this fluorescent dye an excellent replacement to the widely used 6-ROX PCR reference dye.


Figure 1. Stability comparison of 6-ROX versus 6-ROXtra™. Blue bar represents starting fluorescence. Red bar represents remaining fluorescence after 4 weeks at 25 °C.

Additional resources

6-ROXtra™ SE *Superior 6-ROX Replacement*

Polymerase Chain Reaction (PCR)