Protein G binds to most IgG subclasses from human human IgG1, IgG2, IgG3, IgG4, mouse mouse IgG1, IgG2a, IgG2b, IgG3 and rat rat IgG1, IgG2a, IgG2b, IgG2c species. It can binds strongly to goat total Ig, IgG1, IgG2, sheep total Ig, IgG1, IgG2, cow total Ig, IgG1, IgG2. Protein G can bind slightly with total Ig from rabbit, dog, cat, pig and guinea pig. This product can be used for 100-200 times. For frequent use, an aliquot can be stored at 4°C. for 1 month with addition of 0.02% sodium azide NaN3 to the storage buffer. Because this product can purify IgG subclasses from several species of mammals see above, customers can conjugate the purification products they got with SepharoseTM 4B beads to purify secondary antibody.