HiLyte™ Fluor 488 C2 maleimide is an excellent thiol-reactive fluorescent labeling dye that generates the protein conjugates far superior to those of fluorescein derivatives such as FITC. Not only are HiLyte™ Fluor 488 conjugates significantly brighter than fluorescein conjugates, they are much more photostable. Also, fluorescence of HiLyte™ Fluor 488 fluorophore is independent of pH from 4 to 10. This pH insensitivity is a major improvement over fluorescein, which emits its maximum fluorescence only above pH 10.Extinction Coefficient (M-1cm-1): 70,000Fluorescence quantum yield: 0.91Fluorescence Life Time (ns): 4.1