Abstract: Novel adenocarcinoma binding human monoclonal antibody binds preferentially with ADCA antigens and is useful in diagnostic and imaging methods for identifying and locating adenocarcinoma cells, and in therapeutic methods to reduce the reproduction of adenocarcinoma cells. The novel ADCA antigen is useful in methods for diagnosing the presence of adenocarcinoma. The antigen, antibodies, hybridoma, reagents, therapeutic agents and methods of use are aspects of the invention.