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Materials for testing of RNA coronavirus, causing

ROX Reference Dye


ROX (6-carboxy-X-rhodamine) Reference Dye for quantitative polymerase chain reaction (qPCR) serves as an internal reference for normalization of the fluorescent signal when using real-time PCR instruments, which can detect ROX. ROX allows for correction of the well-to-well variation due to pipetting inaccuracies and fluorescence fluctuations. The presence of ROX does not interfere with qPCR amplification [G. Wang, E. Becker, C. Mesa, Optimization of 6-carboxy-X-rhodamine concentration for real-time polymerase chain reaction using molecular beacon chemistry, Can. J. Microbiol. 53, 391-397, 2007]. ROX has different emission spectrum (the excitation/emission maxima are at 586 nm/621 nm, respectively) when compared to SYBR Green I and other probes used for qPCR analyses.

Technical data

Components and Packaging

  • ROX Reference Dye is supplied as a concentrated stock, which can be diluted 50x or 500x, depending on the PCR instrument.
  • Composition: 25 µM ROX, 20 mM Tris-HCl, pH 8.4 and stabilizers. 
  • Packaging: 0.5 ml in plastic tubes. This amount sufficient for 500 or 5000 qPCRs (50 µl each), depending on PCR instrument. 


  • At 4 ± 3°C in the dark. For long-time storage (> 1 month) at -20 ± 5°C.

Purity and Quality Control

  • Each batch of ROX Reference Dye is tested for fluorescence signal and compatibility with PCR.

Recommended ROX Reference Dye final concentrations

  • ROX Reference Dye for qPCR mixtures is used in two concentrations, depending on instrument used:
  • Final concentration 500 nM (diluted 50:1; 1 µl per 50 µl reaction) when using Applied Biosystems 7000, 7300, 7700, 7900HT, StepOne, StepOnePlus etc.
  • Final concentration 50 nM (dilute 500:1; 0.1 µl per 50 µl reaction) when using Applied Biosystems 7500, 7500Fast, Stratagene cyclers etc.).
  • Before use it is important to vortex the ROX Reference Dye.


Cat. No. Product name and specification Amount Price
P971 ROX Reference Dye 500 µl 20.42 EUR