摘要 |
A housing has a chamber containing a low speed, e.g., 6 rpm, rotating shaft of highly polished stainless steel to avoid bubbles and arcing. A fluid containing cells to be electroporated and molecules associated with the electroporation are introduced into the chamber formed by the gap between the shaft and housing in either batch or continuous flow modes. A capacitor network applies alternating positive and negative pulses of high voltage across the electrodes formed by the housing and shaft to electroporate the cells. After a few pulses, a resistive load is placed across the network to reduce the value of the pulses applied to the electrodes for a relatively longer period than the high voltage pulses to a relatively low harmless level. The relative motion of the shaft electrode and stationary housing ground electrode creates shear stress in the fluid causing the cells to change orientation to expose different cell surfaces to the voltage pulses thereby minimizing cell destruction due to excessive voltage application. The housing is cooled by thermoelectric devices to maintain the temperature of the cells at a safe level. |