Isolation of Human Breast Cancer Cells by Metastatic Stage Using Contactless Dielectrophoresis

Dielectrophoresis (DEP) has become a promising technique to separate and identify cells and microparticles suspended in a medium based on their physical and electrical properties. DEP is the motion of a particle in a suspending medium due to the presence of a nonuniform electric field [1]. We have recently developed a robust, simple, and inexpensive technique, contactless dielectrophoresis (cDEP), to provide non uniform electric fields in microfluidic channels required for DEP cell manipulation without direct contact between the electrodes and the sample [2]. In this method, an electric field is created in the sample microchannel using electrodes inserted into two conductive microchambers, which are separated from the sample channel by thin insulating barriers. These insulating barriers exhibit a capacitive behaviour and therefore an electric field can be produced in the main channel by applying an AC field across the barriers [2]. The absence of contact between electrodes and the sample fluid inside the channel prevents bubble formation and avoids any contaminating effects the electrodes may have on the sample. Furthermore, reduced joule heating and a simplified inexpensive fabrication process are the other noticeable advantages of this new technique.