The DyLight™ NHS Ester Quenchers are amine-reactive non-fluorescent dyes that use fluorescent resonance energy transfer (FRET) to quench fluorescent signals resulting from ultraviolet, visible and infrared light-excited fluorescent dyes. These dyes can be efficiently paired with many DyLight™ dyes and other common fluorescent dyes including fluorescein, rhodamine, cyanine and Texas Red® dye.