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 and 633 nm). iFluor® 514 dyes have fluorescence excitation and emission maxima of ~510 nm and ~527 nm respectively. These spectral characteristics make them an excellent alternative to Alexa Fluor® 514 labeling dye and rhodamine 6G (Alexa Fluor® is the trademark of Invitrogen). For some antibody conjugates, iFluor® 514 conjugates are significantly brighter. iFluor® 514 Maleimide is stable and shows good reactivity and selectivity with protein thiol group.