This kit contains everything you need to label antibodies or other proteins with a fluorescent CF® dye succinimidyl ester (CF® dye SE) . Each kit contains reagents for three labeling reactions of up to 1 mg protein per reaction. CF® dyes are Biotium's line of next-generation fluorescent dyes with advantages in brightness, photostability, and conjugate specificity compared to other fluorescent dyes. Blue fluorescent CF®405S dye has excitation/emission at 404/431 nm.