Stellaris® FISH Probes, Custom Assay with Quasar® 670 Dye

Custom Stellaris® RNA FISH Probe Set labeled with Quasar 670® dye to detect your RNA of interest.

Product Description

Stellaris RNA FISH is a RNA visualization method that allows simultaneous detection, localization, and quantification of individual RNA molecules at the cellular level in fixed samples using fluorescence microscopy.

A set of Stellaris RNA FISH Probes is comprised of a pool of up to 48 unique probes, each labelled with a fluorophore, that collectively bind along an RNA target transcript to produce a diffraction limited spot.

Before considering designing a Stellaris RNA FISH Customized Probe Set, please also check out our Stellaris RNA FISH DesignReady Probe Sets for a large selection of professionally designed targets.

We also recommend selecting a Stellaris RNA FISH Positive Control (ShipReady) Probe Set RNA  to complement your experiment. 

Stellaris Buffers are the perfect accompaniment to your experiment, allowing for even more robust RNA detection and analysis through reduced background signal. 

Quasar 670 Dye

The Quasar 670 modification incorporates a fluorescent Quasar 670 dye at the terminus of an oligonucleotide. Quasar 670 fluoresces in the red region of the visible spectrum. It is used as a direct replacement for Cy5 dye.

Special Notes and Considerations: This far red dye is equivalent to Cy5. Due to the characteristics of many light sources, cameras, as well as the chemical nature of this otherwise bright dye, the apparent brightness tends to be lower than that of Quasar 570 and CAL Fluor Red 610. When working with this dye, it is essential to use an anti-fade mounting media. This dye performs best in cultured cells, but is also a good option for avoiding auto-fluorescence in tissue. If your probe set has a high number of probes (35 or higher), Quasar 670 is an excellent option, especially for tissue.

Anti-fade Recommendations: The Quasar 670 dye requires an anti-fade mounting media and is compatible with Vectashield by Vector Labs (H-1000), Prolong Diamond by ThermoFisher (P36961), and Prolong Gold by ThermoFisher (P36930).

How long will my sample last after mounting?: When stored at +2 to +8 °C in the dark, the Quasar 670 signal is fairly stable but should be imaged immediately. Vectashield can extend the life of your sample up to three days.

Filter Recommendation: Our in-house team uses Chroma's 41023-ET-Cy5 single band filter set. Chroma's 49009-ET-Cy5 Narrow Excitation single band filter also fits Quasar 670 well.

Absorption and Emission Spectra for Quasar 670 Dye


  • Name: Quasar 670
  • Formula: C36H47N3O3
  • Absorption maximum (lambda max): 647 nm
  • Extinction coefficient at lambda max: 187,000 M-1cm-1
  • Extinction coefficient at 260 nm: 2,800 M-1cm-1
  • Fluorescence maximum: 670 nm

Design considerations

Please read the tech article titled, “Designing Stellaris RNA FISH Probes” before designing your custom assay.

You can also use Chroma’s Spectra Viewer to check your microscope’s dye filter set compatibility. Use the Stellaris Dyes and Modifications page to select the right dye for your microscope and multiplexing recommendations.

Note I: Due to the variable autofluorescence in the green channel inherent to some cells and tissues, it is not recommended to use FAM for some Stellaris RNA FISH assays. We recommend testing your sample for green channel autofluorescence before ordering FAM labeled sets or ordering an alternative dye that is compatible with your experiment.

Note II: The success rate of Custom Probe Sets depend on many variables, such as imaging platform, operator use of optics, target sequence, transcript number, subcellular localization of transcript, number of probes in the set, space between probes, masking level, sample identity whether cultured cells or fresh or frozen tissue, preparation and handling of sample, and customer's design of probe sets with or without the Stellaris Probe Designer. The customer is responsible for designing a probe set that is compatible with all of the variables mentioned above unique to their platform technologies and model system, and therefore we cannot guarantee the success of Customer Probe Sets, or troubleshoot the designs.

Please contact us by email, phone or using this form for further advise and details. 

Product Citations

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    LGC Biosearch Technologies
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  • 851,00 €
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you need any help?

Please contact:

Dr. Monika Haas

Tel. +49 (0) 6221 71415 16