Dielectric techniques, which include dielectric spectroscopy as well as AC electrokinetic methods such as dielectrophoresis, electrorotation and electro-orientation. can be provide important information about cell viability. A review is given of the different dielectric techniques that have been used for measuring cell viability and their utility. The changes that occur in the cell dielectric properties during apoptotic and different forms of traumatic cell death are discussed and interpreted in terms of the main parameters involved (membrane capacitance and conductance and internal conductivity). (C) 2008 Elsevier Inc. All rights reserved.