mFluor™ Blue 585 dyes are an excellent alternative to RPE since they have the spectral properties equivalent to those of RPE conjugates. mFluor™ Blue 585 dyes are water-soluble, and the protein conjugates prepared with mFluor™ Blue 585 dyes are well excited at 488 nm to give red fluorescence (compatible with TRITC filter). mFluor™ Blue 585 dye and conjugates are excellent blue laser reagents for flow cytometry applications. Compared to RPE, mFluor™ Blue 585 dyes are much more photostable, making them readily available for fluorescence imaging applications while it is very difficult to use RPE conjugates for fluorescence imaging applications due to the rapid photobleaching of RPE conjugates. mFluor™ Blue 585 are small organic dyes, thus they are much more readily conjugated to proteins with much higher yield than PE. AAT Bioquest's mFluor™ dye family provides the largest collection of fluorescent labeling dyes with large Stokes Shift. They are optimized for labeling proteins, in particular, antibodies. These dyes are bright, photostable and have minimal quenching on proteins. They have been validated for multicolor applications, in particular, for spectral flow cytometric applications. They can be well excited by the major laser lines of spectral flow cytometers (e.g., 350, 405, 488, 555, 633 and 647 nm).