The Alexa Fluor® 488 F(ab')2 rabbit anti—goat IgG is labeled with our exceptionally bright, photostable Alexa Fluor® 488 dye (which is spectrally similar to fluorescein) and is prepared from affinity-purified antibodies that react with IgG heavy chains and all classes of immunoglobulin light chains from goat. To minimize crossreactivity, it has been adsorbed against human and rat serum proteins prior to labeling. Conjugates of F(ab')2 fragments are sometimes preferable to whole antibody conjugates for secondary detection, since the absence of the Fc region in F(ab')2 fragments prevents interactions with Fc receptor-bearing membranes.