Abstract
The introduction of biological macromolecules such as DNA, RNA, and proteins into living cells plays a crucial role in the fundamental analysis of cellular functions and mechanisms in living systems. Therefore, we have been developing an effective platform for the in vitro manipulation and analysis of biological cells at the single-cell level based on scanning ion conductance microscopy (SICM) for non-damaging imaging of cells. In this paper, we successfully demonstrated a novel intracellular delivery method of DNA into living HeLa cells via a glass micropipette based on electrokinetically driven flow. We also proposed a vibration-assisted insertion method for penetrating a cell membrane to reduce cell damage. Preliminary insertion tests on a homemade SICM system revealed that the application of the mechanical oscillation can reduce the deformation of cells probably due to an increase in their viscous resistance. Moreover, we also found that a change in the ion current during the insertion process allows us to detect the instant when the micropipette tip penetrates the cell membrane.