IRDye QC-1 Infrared Dye is the First NonFluorescent Quencher.

IRDye® QC-1 Infrared Dye

The first nonfluorescent (dark) quencher compatible with a wide range of visible and near-infrared fluorophores (~500 – 800 nm)

  • Used for FRET (fluorescence resonance energy transfer) applications such as protease assays
  • Efficient nonfluorescent quenching of near-infrared (NIR) dyes
  • Caspase-3 Protease Assay substrate
  • Widest available quenching range – no need to carefully match the donor's fluorescence spectrum with the acceptor's absorbance
  • Pair IRDye QC-1 with any visible or near-infrared fluorophore within its wide wavelength range

IRDye QC-1 quencher can be used in protease assays.

  • Quenches common fluorophores with >97% efficiency1
IRDye QC-1 quencher can be used in protease assays.

Figure 1. Energy that is transferred from the donor (Dem) can be emitted at the acceptor's wavelength (Aem), quenching fluorescence.

Many products from the IRDye Family of infrared dyes are being used in assays from other life science companies:

1. Peng, X et al. A nonfluorescent, broad range quencher dye for Fõrster resonance energy transfer assays. Anal Biochem. 388(2):220-28 (2009)

IRDye QC-1 Absorption Spectrum in 1x PBS IRDye QC-1 Absorption Spectrum in Methanol
Solvent Ext. Coef. M-1cm-1 Absorption Max nm MW g/mole
1xPBS 96,000 737 1243.7
Methanol 98,000 788

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