The objective of this study is to develop a cellular delivery method of biomolecules based on electrokinetic forces. We used a glass needle containing YFP plasmid DNA for studying cells after cellular delivery. Observation of expansion of a HeLa cell during cellular delivery revealed that the direction of electrokinetic flow was dominated by electrophoresis. Penetration of a cell was also detected by measuring an ion current through the needle. Incubation of cells in minimum essential medium was necessary for maintaining long-term cellular activity. Expression of YFP was observed in cells without penetration because of diffusion of the DNA in a solution.
