The mouse anti-rat IFN-γ monoclonal antibody (clone DB-13) is of the IgG1 substype. The DB-13 antibody has shown not to bind with rodent IFN-α1 and -β or to mouse or human IFN-γ and possesses very low neutralizing activity. In Western blot analysis the DB-13 antibody reacts with the 14 kDa and 18 kDa polypeptides present in rat IFN-γ (van der Meide P.H. et al. 1989). Further, the DB-13 antibody is effective in ELISA systems and is applicable in immunohistochemistry (Nennesmo I. et al. 1989 and Yang P. et al. 1998).