This protein labeling kit comprises the blue fluorescent dye CF™405M in succinimidyl ester (SE) form and other necessary materials for labeling 3×1 mg antibody. CF™405M is spectrally similar to Pacific Blue dye. CF CF™405M is as bright as Pacific Blue® dye but is significantly more photostable than the latter. An additional advantage of CF™405M is that it has less spillover in the 525/50 green channel than Pacific Blue® dye due to narrower emission peak, making CF™405M a superior choice in multi-color detection applications. We also offer CF™405S, another 405 nm-excitable dye with an even shorter emission wavelength.Compatible with the NucleoCounter® NC-3000™.