Flow-induced electrokinetic trapping (FIET) is a continuous-flow phenomenon that involves the capture of particles in a recirculating flow pattern that arises from opposing pressure-driven and electro-osmotic flow in a non-uniform channel. Since particles are charged, they also exhibit electrophoresis in an applied electric field. Particle electrophoretic velocity, which is particle-specific, thus also plays a major role in the FIET process. DNA can be very simply trapped and preconcentrated using FIET, which makes FIET attractive for lab-chip microsystems for genetic analysis. With this in mind, the influence of ionic strength (IS) and channel conditioning on FIET of DNA were investigated in this study. At higher IS, the potential needed for trapping was observed to increase significantly, which may require the integration of an additional dilution step into an actual genetic analysis device employing FIET. A more extensive protocol for conditioning the channel yielded a stronger and more stable electro-osmotic flow. Copyright © (2011) by the Chemical and Biological Microsystems Society.