The transposable element Activator (Ac) has been used in several plant species as a tool for gene isolation and characterization. However, it has not been widely utilized in its native host maize, in part, because of a relatively low germinal transposition rate. The propensity of Ac to move to linked sites provides an opportunity to overcome this limitation when Ac elements are distributed at regular intervals throughout the genome. This chapter details the use of such a system in maize through simple genetic manipulations. A detailed protocol is also provided to clone DNA flanking Ac insertions.