CF™ dye goat anti-mouse IgG isotype-specific secondary antibody conjugates are labeled with our exceptionally bright, photostable CF™ dyes. The conjugates are prepared from affinity-purified antibodies that react with Fc portion of the heavy chain of mouse IgG1, IgG2a, or IgG2b. To minimize cross reactivity, the antibodies are cross-adsorbed against other mouse IgG subclasses (IgG2a, IgG2b, IgG3), and human, bovine and rabbit serum proteins. Far red/near-infrared fluorescent CF™680 has excitation/emission maxima at 681/698 nm, and produces the brightest antibody conjugates among spectrally similar dyes. CF™680 is compatible with near-infrared imaging systems.