IRDye^® QC-1 NHS Ester

IRDye QC-1 is the first non-fluorescent (dark) quencher compatible with a wide range of visible and near-infrared fluorophores (~500-800 nm). It has the widest available quenching range, so you do not need to carefully match the donor's fluorescence spectrum with the acceptor's absorbance. IRDye QC-1 quenches common fluorophores with >97% efficiency¹.

For more information, see “Spectral Overlap of IRDye QC-1 Absorption with Common Donor Fluorophores” below.

IRDye QC-1 NHS ester can be used for FRET (fluorescence resonance energy transfer) applications such as protease assays. Recently, it has been paired with IRDye 800CW in optoacoustic studies.

Dye Structure

Properties

• Chemical Formula: C₅₃H₆₂C|N₄Na₃O₁₆S₄
• Molecular Weight: 1243.75 g/mol
• Exact Mass: 1242.24

Absorption Spectrum in 1X PBS

Absorption Spectrum in Methanol

Spectral Overlap of IRDye QC-1 Absorption with Common Donor Fluorophores

Reference

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