Reactive quenchers that act as acceptors in fluorescence resonance energy transfer (FRET) applications.

• Thiol- and amine-reactive quenchers
• One Sample Fluorescence Resonance Energy Transfer (OS-FRET) and FRET quenchers

NFQ1, a non-fluorescent quencher, is used for the One Sample Fluorescence Resonance Energy Transfer (OS-FRET) method employing a non-fluorescent methanethiosulfonate-linked acceptor that can be reversibly coupled to a target sulfhydryl residue via a disulfide bond. After the quenched donor emission is quantitated the acceptor is removed by reduction, enabling measurement of unquenched donor emission in the same sample.

The thiol-reactive quencher, CFQ520 maleimide, has a broad and intense absorption (approximately 520 nm) but no fluorescence, making it useful as an acceptor in fluorescence resonance energy transfer (FRET) applications.

The amine-reactive quencher, CFQ520 succinimidyl ester, has a broad and intense absorption (approximately 520 nm) but no fluorescence, making it useful as an acceptor in fluorescence resonance energy transfer (FRET) applications.

N-(6-Aminohexyl)maleimide is a cross-linking reagent that can react with an amine-reactive group and a thiol group.