HiLyte™ Fluor 555 acid, SE is an excellent amine-reactive fluorescent labeling dye that generates the protein conjugates that are only slightly red-shifted compared to those of Cy3 dyes, resulting in an optimal match to filters designed for Cy3 dyes. HiLyte™ Fluor 555 is more photostable than Cy3, providing researchers with additional time for image capture. Additionally, our in-house data indicated that HiLyte™ Fluor 555 is superior to Cy3 in fluorescence polarization-based assays. Extinction Coefficient (M-1cm-1): 150,000 Fluorescence quantum yield: 0.10 Fluorescence Life Time (ns): 0.3