Nup98 is a component of nuclear pore complexes, which are large protein assemblies embedded in the nuclear envelope. Previous studies have shown that Nup98 interacts with several transport factors and plays a critical part in nuclear trafficking. However, the mechanism by which Nup98 contributes to nuclear trafficking is not clear. The present study reports on the preparation of a monoclonal antibody (MAb) directed against human Nup98. The antibody was produced by the hybridization of mouse myeloma cells with lymph node cells from an immunized rat. This antibody, MAb 2H10, specifically recognized Nup98, as evidenced by immunoblotting using a nuclear membrane fraction. In immunostaining using MAb 2H10, a punctuate nuclear rim staining pattern was observed. This MAb will be useful in immunoblotting and immunolocalization experiments in various cells and tissues, as well as further analyses of the biological function and cellular dynamics of this protein.