Energy dissipation as a key factor for electroporation of protoplasts

Abstract

Energy dissipation (epsilon) during electroporation was theoretically determined to be epsilon = 0.5CV02 for the various combinations of capacitance (C) and initial voltage (V0). Experiments on asparagus protoplasts established that electroporation efficiency (EE) and survival rate were directly proportional to energy dissipation during electroporation. A positive linear relationship exists between energy dissipation per unit volume and EE, whereas energy dissipation per unit volume and survival rate of protoplasts are related in a negative linear manner. At the same energy level, longer time constants were more effective at increasing EE. This suggests that energy dissipation approximating rectangular waveforms is more important than that dissipated as sharply decaying exponential waveforms. With energy as the key parameter, the optimization of electrical parameters for efficient electroporation is greatly simplified, is not machine-dependent, and generally applies to all species.

The rate of electrical energy dissipation (power) and the RC constant unify all electroporation parameters

“…Each data point corresponds to quadruple experiments with the same high statistical significance as in ref. 4 (Chen et al 1998) (also see legend of Fig. 1).…”

“…3). In fact, we showed earlier that electroporation conditions can be standardized if they are based on the amount of electrical energy dissipated into the electroporation cell and not on the above electrical parameters considered separately (Lurquin 1997, 2002; Chen et al 1998). …”

“…The importance of energy dissipation during electroporation was first established theoretically (Lurquin 1997), and soon demonstrated empirically using plant protoplasts (Chen et al 1998). In addition to energy dissipation, the significance of the rate of energy dissipation was raised but not solved (Lurquin 1997).…”

“…This issue is solved here by re-analyzing and computing older energy data obtained with plant ( Asparagus officinalis ) protoplasts as reported in ref. (Chen et al 1998). These authors noticed an effect of the RC constant on electroporation efficiency, but did not elaborate further.…”

“…1Electroporation efficiency ( EE ) of Asparagus officinalis protoplasts as a function of power ( P ) dissipation in the electroporation medium at various pulse lengths. Open circles RC = 100 ms, closed circles RC = 50 ms, open triangles RC = 22 ms, closed triangles RC = 10 ms. Data points were computed from energy and average electroporation efficiency values as reported in (Chen et al 1998). All data points preserve the original statistical significance of electroporation efficiency based on regression analysis and LSD 0.05 as in (Chen et al 1998).…”