AAT Bioquest's iFluor® dyes are optimized for labeling proteins, in particular, antibodies. These dyes are bright, photostable and have minimal quenching on proteins. They can be well excited by the major laser lines of fluorescence instruments (e.g., 350, 405, 488, 514, 555, 633, 647 and 808 nm). iFluor® 660 dyes have fluorescence excitation and emission maxima of ~660 nm and ~680 nm respectively. These spectral characteristics make them a unique acceptor for preparing PE, APC and PerCP tandems that are widely used in flow cytometry applications. iFluor® 660 Maleimide is stable and shows good reactivity and selectivity with protein thiol group.