Modeling DNA Motion Under Electrostatic Repulsion Within a Living Cell

We are developing a new technique, called nanoinjection, to insert foreign DNA into a living cell. Such DNA transfection is commonly used to create transgenic organisms vital to the study of genetics, immunology, and many other biological sciences. In nanoinjection, DNA, which has a net negative charge, is electrostatically attracted to a micromachined lance. The lance then pierces the cell membranes, and the voltage on the lance is reversed, repelling the DNA into the cell. This paper presents a mathematical model to predict the motion (trajectory) of DNA particles within a cell in the presence of the electric field developed by the lance and the substrate. The model is used to predict the scattering of DNA through the cell due to electrostatic repulsion. We are currently preparing experiments which will be used to validate the model.