Molecular Probes nonfluorescent quenchers and photosensitizers—Table 1.10

Dye	Abs *	Extinction Coefficient †	Amine-Reactive Dyes ‡	Notes
Dabcyl	453	32,000	D2245 (SE)	Broad and intense visible-wavelength absorption Efficient energy transfer acceptor from blue- and green-fluorescent dyes in FRET applications
Malachite green	628	76,000	M689 (ITC)	Nonfluorescent photosensitizer
QSY 7	560	90,000	Q10193 (SE)	Essentially nonfluorescent quencher Broad visible-wavelength absorption Efficient energy transfer acceptor from UV light–excited green- and orange-fluorescent dyes in FRET applications
QSY 9	562	88,000	Q20131 (SE)	Essentially nonfluorescent quencher Spectrally similar to QSY 7, but with enhanced water solubility Efficient energy transfer acceptor from UV light–excited green- and orange-fluorescent dyes in FRET applications
QSY 21	661	90,000	Q20132 (SE)	Essentially nonfluorescent quencher Long-wavelength absorption Efficient energy transfer acceptor from red- and near-infrared–fluorescent dyes in FRET applications
QSY 35	475	23,000	Q20133 (SE) §	Nonfluorescent quencher Spectrally similar to dabcyl Efficient energy transfer acceptor from blue- and green-fluorescent dyes in FRET applications
* Absorption (Abs) maxima, in nm. † Molar extinction coefficient in cm^-1M^-1 determined at the wavelength listed in the column headed Abs. These values may vary with the environment, particularly for the QSY 35 dye. ‡ (ITC) = Isothiocyanate. (SE) = Succinimidyl ester.

For Research Use Only. Not for use in diagnostic procedures.

Molecular Probes Nonfluorescent Quenchers and Photosensitizers—Table 1.10