Alexa Fluor 680 goat anti—rabbit IgG is labeled with our superior, far-red—fluorescent Alexa Fluor 680 dye and is prepared from affinity-purified antibodies that react with IgG heavy chains and all classes of immunoglobulin light chains from rabbit. To minimize crossreactivity, it has been adsorbed against human IgG, human serum, mouse IgG, mouse serum and bovine serum. We also provide a version of the same antibody that has been cross-adsorbed against additional species (Catalog number: A-21109). Fluorescence of this long-wavelength Alexa Fluor dye is not visible to the human eye but is readily detected by most imaging systems.