We produced a rabbit monoclonal antibody (MAb) against human CDC25C phosphatase. The antibody reacts with a minimal epitope between amino acids 291-295 in the highly conserved C-terminal region of CDC25C. The antibody recognizes denatured CDC25C of recombinant and mammalian origin in Western blot analysis. The corresponding rabbit polyclonal serum is able to immunoprecipitate the native protein, but this ability has been lost during the selection procedure. Although the production of the rabbit MAb requires more effort and patience than the mouse MAb technology, it offers a true alternative in case of antigens that are not immunogenic in mice.