Alexa Fluor 647 goat anti—rabbit IgG is labeled with our exceptionally bright, far-red—fluorescent Alexa Fluor 647 dye (which is spectrally similar to Cy5 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 (A-21245). Fluorescence of this long-wavelength Alexa Fluor dye is not visible to the human eye but is readily detected by most imaging systems.