Recently, electrode-based Dielectrophoresis (eDEP) has been used for particle manipulation by means of triangular electrodes. In this theoretical and numerical study, a microchannel with quarter-of-ellipse electrodes is presented and a detailed comparison with triangular electrodes is provided. Electric field, resultant DEP force, and particle trajectories for each microchannel are evaluated by means of COMSOL Multiphysics 4.4. Afterwards, focusing and separation efficiencies of the systems are assessed and compared. Finally, separation efficiency of our proposed model for live and dead cells is compared with that of our previous model published in the literature [1]. It is demonstrated that our proposed new model has higher lateral DEP force, responsible for cell separation, than the previous triangular-electrode model had. This feature is reflected in the 96% focusing efficiency for 10-micron particles and 100% separation efficiency for live and dead mammalian cells. © 2018 Sharif University of Technology. All rights reserved.