Assessment of cytoplasm conductivity by nanosecond pulsed electric fields

the aim of this paper is to propose a new method for better assessment of cytoplasm conductivity, which is critical to the development of electroporation protocols as well as insight into fundamental mechanisms underlying electroporation. Methods: for this goal, we propose to use nanosecond electrical pulses to bypass the complication of membrane polarization and a single cell to avoid the complication of the application of the "mixing formulas". Further, by suspending the cell in a low-conductivity medium, it is possible to force most of the sensing current through the cytoplasm for a more direct assessment of its conductivity. Results: for proof of principle the proposed technique was successfully demonstrated on a Jurkat cell by comparing the measured and modeled currents. Conclusions: the cytoplasm conductivity was best assessed at 0.32 S/m and it is in line with the literature. Significance: The cytoplasm conductivity plays a key role in the understanding of the basis mechanism of the electroporation phenomenon and in particular a large error in the cytoplasm conductivity determination could result in a correspondingly large error in predicting electroporation. Methods for a good estimation of such parameter become fundamental.