A Microfluidic Platform for In Situ Studies of Bacteria Electroporation

Abstract

Electroporation of dye‐labeled bio‐molecules into bacteria has proven to be a valuable route for single‐molecule tracking in living cells. However, control over cell viability, electroporation efficiency, and environment conditions before, during, and after electroporation is difficult to achieve in bulk experiments. Here, a microfluidic platform is presented capable of single‐cell electroporation with in situ microscopy and demonstrate delivery of DNA into bacteria. Via real time observation of the electroporation process, it is found that the effect of electrophoresis plays an important role when performing electroporation in a miniaturized platform and show that its undesired action can be balanced by using bipolar electrical pulses. It is suggested that a low temperature of the sample during electroporation is important for cell viability due to temperature‐dependant viscoelastic properties of the cell membrane. It is further found that the presence of low conductive liquid between cells and the electrodes leads to a voltage divider effect that strongly influences the success of on‐chip electroporation. Finally, it is concluded that electroporation is a highly stochastic process and envision that the microfluidic system presented here, capable of single‐cell read‐out, can be used for further fundamental studies to increase the understanding of the electroporation process in bacterial cells.