High-Throughput and Real-Time Study of Single Cell Electroporation Using Microfluidics: Effects of Medium Osmolarity. Biotechnology and Bioengineering. vol 95

Abstract: Electroporation has beenwidely accepted as an important tool for the delivery of exogenous molecules into cells. Previousmechanistic studies have been carried out by observing either the average behavior from a large population of cells or the response from a small number of single cells. In this study, we demonstrated a novel microfluidicmethodwithhigh throughput (up to30Hz) for real-time studies of single cell electroporation events. Electroporation occurred when cells flowed through a section of a microfluidic channel defined by special geometry. A CCD camera was used to monitor the response of cells starting from the onset of the electro-poration. We studied the swelling of Chinese hamster ovary cells and the rupture of cell membrane during electroporation using this technique. We applied buffers with different osmolarities to investigate the effects of medium osmolarity, based on results from a population of single cells. We were able to establish the distributions of the rates of swelling and membrane rupture in the cell population.We also explored establishing the correlation between the property (the cell diameter) and the behavior (the swelling rate) of single cells.Our results indicated that the processes of swelling and rupture occurred more rapidly in the hypotonic or hypertonic buffers than in the isotonic buffer. Statistical analysis did not reveal strong linear correlation between the cell size and the swelling rate. These proof-of-concept studies reveal the potential of applyingmicrofluidics to study electroporation of a cell population at single cell level in real time with high throughput. The limitations associatedwith this approach were also addressed. 2006 Wiley Periodicals, Inc