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Thermo Scientific™ DyLight™ Quencher Specialty Dyes

Quench fluorescence resonance energy transfer (FRET) applications involving DyLight Fluors or other fluorescent probes using these non-fluorescent dyes.

Supplier:  Thermo Scientific™ 84509

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Catalog No. PI84509

This item has been discontinued by the manufacturer and is no longer available. Please call customer service for assistance: 1-800-766-7000.



Thermo Scientific™ DyLight Quencher Specialty Dyes are for efficient paring with DyLight Fluors and other commercial fluorescent dyes for qualitative and quantitative fluorescence resonance energy transfer (FRET) applications.

DyLight Quencher Specialty Dyes are a family of non-fluorescent dyes designed for fluorescence quenching in FRET applications. The optimal quencher dye can be selected based upon its characteristic absorption properties that match the emission of a corresponding fluor. Each dye contains an amine-reactive NHS ester for simple modification of antibodies, proteins, peptides or other biomolecules through amide bond formation.


  • Large selection– the largest family of dyes available for far red-emitting fluorescence applications

  • NHS ester reactive group–allows immediate labeling of antibodies, proteins, peptides and other amine-containing molecules through amide bond formation

Criteria to consider when choosing a DyLight Quencher Specialty Dye:

  • Absorption wavelength–choose the quencher dye with the absorbance wavelength that matches the emission of your fluorophore and the instrument.
  • Water solubility–choose a dye based on its relative hydrophilicity, which directly correlates to the number of negatively-charged sulfonates it has on its core structure. More hydrophilic dyes are best at maintaining water solubility of a labeled antibody and limiting the nonspecific binding of the conjugate. More hydrophobic dyes often are best at penetrating tissues and cell membranes in vivo, meaning that dyes with fewer sulfonates may work best for some applications.
  • DyLight dye selection–the broad selection of red-emitting dyes allows a number of candidate dyes to be tested in an application for optimal performance.

Recommended for:

FRET; Other quenching applications



DyLight 641Q NHS Ester
Non-fluorescent NHS ester activated Benzopyrillium  quencher
1 mg
1 use to label a total of 7mg of IgG using typical conditions


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