Dynamic Dielectrophoretic Levitation of Living Individual Cells

The levitation of lone live cells by means of dielectrophorectic force provides a means of determining the relative polarization of the cells and their aqueous support medium. When done over a range of frequencies, a spectrum of dielectric (polarization) responses is obtained which serves to characterize a single living cell. In this manner, individual cells of several microorganisms, Saccharomyces cerevisiae and Netrium digitus, were investigated in the frequency range 102-106 Hz. These and related prior studies showed that the positive dielectrophoresis, i.e., where the suspended particle has a greater net polarization than the suspending medium, can be used to show subtle differences between species and even between cells of the same culture.