This paper demonstrates the use of Ultra-High Frequency Dielectrophoresis to sort populations of biological cells. The principal aim of this lab-on-chip cytometer is to sort in a continuous flow different types of cells in suspension based on their dielectrics properties. To achieve this objective, this cytometer combines hydrofluidics and repulsive dielectrophoresis forces. We also show the importance to apply at cells a proper electric field at a specific frequency range to produce different force intensities and associated trajectory deflections. The device efficiency will be illustrated with an example of mesenchymal cells sorting.