Different cell viability Assays following electroporation in vitro

Abstract

Exposure of cells to high intensity electric fields can lead to death of some cells due to irreversible electroporation or due to electroporation-induced secondary effects. If cells are exposed to these fields in the presence of various exogenous molecules, cell death can also be induced due to their activity in the cells. In all these cases, mechanisms of cell death as well as the time periods over which death of these cells occur are highly variable. Therefore, application of different cell viability assays can lead to inconsistent results, either depending on the assay itself or the application time. The aim of this chapter is to provide a brief presentation of viability assays that have been employed in electroporationbased applications and provide a short discussion on choosing the specific cell viability assay to properly interpret the obtained results. Since most of cell viability assays (all tetrazolium salt-based assays, resazurin assay, calcein acetoxymethyl ester (calcein AM) assay, crystal violet (CV) assay, evaluation of necrosis and/or apoptosis, etc.) are applied at time points when death of some cells in the treated population is still in progress, they cannot provide precise viability results. Therefore, those who seek to evaluate cell viability as precisely as possible should rely on end-point clonogenic assay. Other cell viability assays can be applied in parallel with clonogenic assay or at least should be tested in pilot experiments before they are employed routinely in a specific set of experiments.