Cytokinins are involved in in vitro shoot initiation, although little is known about their mode of action. As the first step in localizing cytokinin synthesis, we present a cloning and expression strategy for the isopentenyl transferase (ipt) gene. The source of the Agrobacterium tumefaciens ipt gene was a 7.2 kb Eco RI fragment isolated from pBREF7 (Dr. Ann Smigocki, USDA, Beltsville, MD). The ipt gene was amplified by polymerase chain reaction (PCR) and cloned into pMal-cRI (New England Biolabs, Beverly, MA). Using the pMAL-cRI expression and purification system, the isopentenyl transferase protein will be purified for antibody production. These antibodies will be used in future work to localize the isopentenyl transferase enzyme.