This highly cross-adsorbed 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 bovine IgG, goat IgG, mouse IgG, rat IgG and human IgG. Fluorescence of this long-wavelength Alexa Fluor dye is not visible to the human eye but is readily detected by most imaging systems.