Rapid generation of cells for ion channels assays: Efficient, large scale transfection using the MaxCyte STX

The MaxCyte® STX™ Scalable Transfection System uses a proprietary flow electroporation technology that can transfect up to 1E10 cells with target, reporter and protein expression plasmids, as well as other molecules, in less than 30 minutes. Transfected cells can be assayed immediately or cryopreserved for future use. Here we demonstrate the use of the MaxCyte STX system in coordination with Corning’s ® HYPERFlask® Cell Culture Vessel to provide an efficient and economical solution for culturing large numbers of adherent CHO cells before and after transfection. The HYPERFlask Cell Culture Vessel features Corning’s HYPER (High Yield PERformance) technology, which utilizes a gas permeable film to provide gas exchange between the internal culture environment and the external atmospheric environment. The unique, space-saving, 10-layer film design results in 1720 cm2 cell growth surface area, which is approximately 10 times that of a normal T-175 flask. We also show that cells transfected with a plasmid encoding a Kv1.3-GFP fusion protein exhibited good seal formation and strong potassium currents following large scale electroporation and cryopreservation. Ion channel activity was assayed on the Sophion QPatch automated patch clamp system. High viability and consistent levels of expression were obtained in three independent large scale electroporations, illustrating robustness and reproducibility of the transfection process. These results demonstrate that the MaxCyte STX system offers a time and labor saving alternative to stable cell line generation for ion channel assays.