The Alexa Fluor 647 chicken anti—rat 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 rat. Chicken antibodies lack a classic "Fc" domain and will not bind to mammalian IgG Fc receptors. To minimize crossreactivity, the antibody has been adsorbed against human and rabbit IgG prior to conjugation. Fluorescence of this long-wavelength Alexa Fluor dye is not visible to the human eye but is readily detected by most imaging systems.