CF405M streptavidin conjugate is prepared from high quality streptavidin and the fluorescent dye CF405M. CF405M (Ex/Em = 408/452 nm) is a blue fluorescent dye spectrally similar to Pacific Blue? dye. CF405M is as bright as Pacific Blue? dye but is significantly more photostable than the latter. An additional advantage of CF405M is that it has less spillover in the 525/50 green channel than Pacific Blue? dye due to narrower emission peak, making CF405M a superior choice in multi-color detection applications. We also offer streptavidin conjugated to CF405S (catalog no. 29032), another 405 nm-excitable dye with an even shorter emission wavelength.