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.