We study a system in which DNA or RNA molecules are driven through a nanometer-scale pore ("nanopore") by an external electric field. This process can be observed at the single molecule level because the passage of one DNA or RNA molecule through the pore causes a transient obstruction in the ionic current flowing through the pore. This system shows promise in nucleic acid detection and characterization applications and it also constitutes a unique model system that may give new insight into biologically relevant, nanoscale physical and chemical processes. The nanopore we study is formed by the staphylococcuc aureus alpah-hemolysin protein (alpha-HL). A schematic diagram of RNA being electrically driven through alpha- is shown below.