Dielectrophoresis (DEP) is a well-known technique for particle manipulation that has enabled a number of applications such as sorting, patterning, and filtering of many different cells, particles and molecules. The technique exploits the interaction between an electrical dipole induced on polarizable particles and an electric field gradient. Particles can be made to move towards a gradient maxima (positiveDEP) or minima (negativeDEP) depending on the polarizability differences between the targeted particle and the suspending media. Furthermore, a given particle suspended in a given media can display both DEP behaviors as the frequency of the field changes. This is illustrated in the videos below where a population of M. smegmatis cells (shiny dots) can either be attracted to the carbon electrodes (dark circles) as in positiveDEP, or repelled from them as in negativeDEP. Note that the sample is exactly the same and only the frequency of the applied field changes.