Dynamic dielectrophoretic levitation of living individual cells

The levitation of lone live cells by means of dielectrophoretic 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 ell. In this manner, individual cells of several microorganisms,Saccharomyces cerevisiae andNetrium digitus, were investigated in the frequency range 10² to 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 when using this technique.