Interfacing devices with cells

To detect electrical properties of cells, we have developed a method called iso-dielectric separation (IDS), where cells are placed in a spatially varying electric field and a spatially varying conductivity gradient that forces them to the location in a channel where their net polarizability (p) is zero. At that location, the force on the cell, given by the dielectrophoretic force (F - p·¿E) will go to zero. Cells with different polarizabilities will end up in different locations in the channel, thus separating cells based upon electrical properties. The physical implementation of the method is described in Figure 3, and consists of a glass chip with patterned electrodes to create the field, along with microfluidics to deliver cells and create the conductivity gradient.