The change in the membrane potential of Jurkat cells in response to nanosecond pulsed electric fields was studied for pulses with a duration of 60 ns and maximum field strengths of ∼100 kV/cm (100 V/cell diameter). Membranes of Jurkat cells were stained with a fast voltage-sensitive dye, ANNINE-6, which has a subnanosecond voltage response time. A temporal resolution of 5 ns was achieved by the excitation of this dye with a tunable laser pulse. The laser pulse was synchronized with the applied electric field to record images at times before, during, and after exposure. When exposing the Jurkat cells to a pulse, the voltage across the membrane at the anodic pole of the cell reached values of 1.6 V after 15 ns, almost twice the voltage level generally required for electroporation. Voltages across the membrane on the side facing the cathode reached values of only 0.6 V in the same time period, indicating a strong asymmetry in conduction mechanisms in the membranes of the two opposite cell hemispheres. This small voltage drop of 0.6–1.6 V across the plasma membrane demonstrates that nearly the entire imposed electric field of 10 V/μm penetrates into the interior of the cell and every organelle.
展开▼
机译：对于持续时间为60 ns，最大场强约为100 kV / cm（100 V /电池直径）的脉冲，研究了Jurkat细胞响应纳秒脉冲电场的膜电位变化。 Jurkat细胞膜用快速电压敏感染料ANNINE-6染色，该染料具有亚纳秒的电压响应时间。通过使用可调激光脉冲激发这种染料，可以达到5 ns的时间分辨率。激光脉冲与施加的电场同步，以在曝光之前，期间和之后记录图像。当将Jurkat细胞暴露于脉冲时，在15 ns后，细胞阳极极处的膜两端电压达到1.6 V，几乎是电穿孔通常所需电压水平的两倍。在同一时间段内，面对阴极的那一侧的膜两端的电压仅达到0.6 V，这表明两个相对的细胞半球的膜的传导机制存在强烈的不对称性。穿过质膜的0.6–1.6 V的小电压降表明，几乎施加的10 V /μm的整个电场都渗透到细胞内部和每个细胞器中。
展开▼
