AAT Bioquest's mFluor™ dyes are developed for flow cytometry-focused applications. These dyes have large Stokes Shifts, and can be well excited by the laser lines of flow cytometers (e.g., 405 nm, 488 nm and 633 nm). mFluor™ Blue 570 dyes have fluorescence excitation and emission maxima of ~553 nm and ~570 nm respectively. Like RPE protein, it has a broad absorption spectrum, making its conjugates readily excitable by 488 nm blue laser. These spectral characteristics make mFluor™ Blue 570 an excellent alternative to RPE labeling protein. mFluor™ Blue 570 is a small organic molecule that is much easier to use than the RPE labeling protein. mFluor™ Blue 570 SE is reasonably stable and shows good reactivity and selectivity with protein amino groups. This kit has all the essential components to perform two separate labeling reactions with no column purification needed. Each of the two vials of mFluor™ Blue 570 provided in the kit is optimized for labeling ~50 µg antibody. mFluor™ Blue 570 antibody labeling kit provides a convenient method to label small amounts of monoclonal, polyclonal antibodies or other proteins (>10 kDa) with the mFluor™ Blue 570 SE dye.