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Cat. No.
500 x 20µl Reactions
2000 x 20µl Reactions
5000 x 20µl Reactions

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Outstanding assay reproducibility, sensitivity and robustness from both DNA and RNA templates, under fast thermal cycling conditions.

Product Highlights

  • Reproducible – consistent results between technical replicates for increased confidence in results
  • Robust – reliable, accurate detection of DNA and RNA targets from a broad range of sample types
  • Sensitive – reliable quantification of low abundance targets and scarce samples
  • Fast – delivers reproducible, accurate assay results in as little as 30 minutes
  • Efficient – excellent performance in multiplex assays
  • Specific – antibody-mediated hot-start DNA polymerase minimizes non-specific amplification for improved assay sensitivity and reliability

Product Description

The SensiFAST™ Probe Lo-ROX Kit has been developed for fast, highly reproducible real-time PCR and has been validated on all commonly-used real-time instruments that require a low concentration of the passive reference dye ROX. SensiFAST Probe has been formulated for use with dual-labelled probes, including TaqMan®, Scorpions® and molecular beacon probes.

A combination of the latest advances in buffer chemistry and PCR enhancers, together with an antibody-mediated hot-start DNA polymerase, ensures that the SensiFAST Probe Kit produces reliable assay results under fast thermal cycling conditions. Furthermore, SensiFAST Probe has been optimized to deliver excellent results in multiplex assays.

The SensiFAST Probe Lo-ROX Kit has been optimized to deliver optimal performance in tandem with the SensiFAST cDNA Synthesis Kit, which offers fast, unbiased cDNA synthesis, without compromising cDNA yield or coverage.


  • Gene expression analysis
  • DNA / RNA target detection
  • Copy number variation (CNV) analysis

Introduction to SensiFAST

Overview, features and benefits of the SensiFAST product family

One-step Vs. Two-step real-time RT PCR

A discussion of the pros and cons of each detection strategy.

Application Note

SensiFAST™ Probe Lo-ROX Kit

I performed a comparison of Meridian's SensiFAST™ Probe against several other qPCR master mixes. The Meridian product performed the best overall in terms of efficiency, sensitivity, lower in cost. I have also been very impressed Meridian's customer service.

Tiffany Kosch, James Cook University, Townsville, Australia




500 x 20 µL Reactions

2000 x 20 µL Reactions

5000 x 20 µL Reactions

SensiFAST Probe Lo-ROX Mix (2x)

5 x 1 mL

4 x 5 mL

10 x 5 mL



BIO-84005: 500 x 20 µL Reactions: 5 x 1 mL
BIO-84020: 2000 x 20 µL Reactions: 4 x 5 mL
BIO-84050: 5000 x 20 µL Reactions: 10 x 5 mL

Storage & Stability

All kit components should be stored at -20°C upon receipt. When stored under the recommended conditions and handled correctly, full activity of the kit is retained until the expiry date on the outer box label.

Avoid exposure of the ROX™ to light.

Shipping conditions

Shipped on dry/blue ice.



"We recently trialled Meridian's SensiFAST cDNA Synthesis Kit and the ...

""For SensiFAST Probe Lo-ROX Kit “Overall, the reagent is good and ...


This is not possible because the SYBR® is pre-mixed into the SensiFAST SYBR® mastermix.

SensiFAST One-Step Kits can be used with most RNA/cDNA templates. To give you some idea of a few of the types of templates used with these kits:

Human - Rosato R.R., et al. Cancer Res. 67: 9490-500 (2007)
Rat - Remund K., et al. Expt. Lung Res. 35: 359-370 (2009)
Drosophila - Brown A.E., et al. PloS ONE 4: e4490 (2009)
Nitrogen-fixing bacteria - Bahlawane C., et al. Mol. Plant-Microbe Inter. 21: 1498-1509 (2008)
Diphtheria bacteria - Jochmann N., et al. Microbiology 155: 1459-1477 (2009)
Green algae - Wobbe L., et al. PNAS 106: 13290-13295 (2009)
Bovine virus - Park S-I., et al. J. Virol. Methods. 159: 64-6 (2009)

For cDNA/DNA templates SensiFAST SYBR® and Probe kits are used. To give you some idea of a few of the types of templates used with these kits:

Stem Cell - Bernardo A.S., et al. Stem Cells 27(2): 341 -351 (2008)
Cow - Baumert A., et al. J. Dairy Research 76(3): 356-364 (2009)
Mouse - Hoyles R.K., et al. Arthritis Rheum. 58(4): 1175-88 (2008)
Quail - De Winter P., et al. British Poultry Science 49(5): 566 – 573 (2008)
Insect - Bass C., et al. Malaria journal 6 111 (2007)
Fish - Miller M.R., et al. J. Nutr. 138(11): 2179-2185 (2008)
Crab - Wilcockson D.C. & Webster S.G. Gen. & Comp. Endo. 156: 113–125 (2008)
Nematode - Murray S.L., et al. Mol. Plant-Microbe Interactions 20(11): 1431–1438 (2007)
Plant - Hecht V., et al. Plant Physiology Preview DOI:10.1104/pp.107.096818 (2007)
Yeast - Kawauchi J., et al. Genes & Dev. 22: 1082-1092 (2008)
E.coli Bacteria - Saeed H.A., et al. Research J. Microbiology 4(4); 173-177 (2009)
Virus - Muscillo M., et al. Water, Air, & Soil Pollution 191: 1-4 (2008)

Although SensiFAST kits have been designed for fast PCR on the new generation of fast machines, they will work equally well for standard or fast PCR protocols on all real-time PCR machines.

Polymerase activity during the reaction set-up causes non-specific amplification including primer-dimer formation. To avoid non-specific amplification the polymerase is only activated after heating at 95°C for 2-3 minutes.

When comparing SensiFAST with a mix from another supplier we strongly recommend to use the suggested conditions for PCR setup and cycling. Every real-time mix has its specific composition and different properties. That’s why they should be tested with their specific conditions, mostly this is possible on different plates only. We recommend amplifying from a ten-fold template dilution series. Loss of detection at low template concentration is the only direct measurement of sensitivity. An early Ct value is not an indication of good sensitivity, but rather an indication of speed.

The recommended PCR conditions in the manual refer to the set-up of TaqMan probe-based PCR. If you want to use other probe types, it may be necessary to adapt the PCR setup conditions, please refer to the relevant literature. In case of hybridization probes it would be necessary to switch to a three-step PCR setup with annealing at 60°C and extension at 72°C and acquire the data at the end of the annealing phase (the exact annealing temperature may vary and has to be optimized for a specific assay). The two-step protocol with an annealing / extension step at 60°C would lead to the degradation of these probes, which is wanted for TaqMan but not for hybridization probes. If you have further questions, please contact Meridian Technical Support.

The emission recorded from ROX during the baseline cycles is used to normalize the emission recorded from the reporter (SYBR®) in later cycles in some instruments. ROX compensates for small fluorescent fluctuations such as bubbles and well-to-well variations that may occur.

The amount of the ROX passive reference dye needed varies depending on the instrument optics. Our SensiFAST kits have been optimized for all these different instruments (see Product Selection Tool).

SYBR® Green I is an inexpensive, universal dye which binds to all dsDNA. It can be easily used in combination with a simple primer pair to detect PCR products in real-time. This dye is very attractive for researchers analysing lots of different genes.

The probe system is always specific, probes only detect the gene of interest. It is also possible to distinguish between similar sequences with small differences like SNPs or mutations. In general, probe assays need less optimization than SYBR® Green I assays.

This method is only effective if all the researchers in the laboratory, or using the thermocycler, are all using a dUTP/dNTP and UNG system. If even one researcher is not, it ceases to be an effective control. Using dUTP has also been shown to be inefficient as it increases the Ct values by reducing reaction efficiency. Most labs do not need to use the dUTP method of control, optimised protocols will allow high specificity of PCR and good lab practices (using disposable consumables, the use of filter tips and maintaining a separate area for PCR set-up and PCR amplification and any post-PCR analysis) virtually eliminate the risk of cross contamination.

In a one-step reaction the reverse transcription reaction and the real-time PCR reaction are done in one tube, making this a closed tube assay, so contamination can be avoided. It saves pipetting steps and time and is easy in handling, making it ideal for high throughput screening. In a two-step reaction the reverse transcription reaction and the real-time PCR reaction are done in separate tubes. It gives a more flexible way of working in that the cDNA can be used for more than one real-time PCR reaction and can be archived, eliminating the need to continually isolate RNA. For convenience Meridian sells the SensiFAST cDNA Synthesis Kit separately if you wish to take a two-step approach.

A possible reason is that the template amount is too concentrated. An early Ct may impair the baseline correction and may cause these strange curves. We suggest to dilute the template. Alternatively if the curve is flattened, this may be due to inhibitors in the reaction. Running a serial dilution of your sample will dilute the inhibitor concentration, if this corrects the problem, you will either need to go back and re-purify your template, or use it at a lower concentration, where the inhibitor effect has been diluted out.