Abstract: A novel method is provided for delivering nucleic acid molecules to the cells of an organism by pulse voltage delivery. The method involves the combination of formulated nucleic acid molecules with devices for injecting the molecules by pulse voltage or an electrical field. Disclosed are compositions and methods for enhancing the administration to and uptake of nucleic acids in a mammal. The methods disclosed provide an increased transfection and/or gene delivery efficiency by enhancing the uptake of formulated nucleic acid molecules by applying an electrical field which destabilizes the cellular membrane thereby opening pores or passageways which allow extracellular material to be introduced to the cell. Also disclosed are examples which demonstrate that the combination of formulated nucleic acid molecules and pulse voltage injection methods results in immune responses which are superior to those obtained by conventional means of delivery.