SIGNIFICANCE OF TREATMENT ENERGY IN CELL ELECTROPERMEABILIZATION

The effect of applied electrical energy on cell survival and permeabil ization of the plasma membrane under in vitro conditions were examined . Cell viability was measured with a colony-forming assay, permeabiliz ation of the plasma membrane by means of propidium iodide (PI) uptake. Cells were exposed to five regimens of electrical treatment parameter s. For a given voltage, applied electrical energy was the same for all regimens. In all applied regimes, cell survival was comparable. The d ifferences in PI uptake between applied regimens were significant. The highest percentage of stained living cells (76%) was observed with fo ur long pulses (200 mu s) with a repetition frequency of 0.5 Hz at 200 V. At regimens with higher numbers of shorter pulses, the percentage of stained living cells was considerably lower. According to our resul ts, total applied electrical energy is not a determinant parameter for drug uptake and cell survival under in vitro conditions.