Electric-Field Manipulation of a Cell-Free Gene Expression Reaction

Biological systems are regulated dynamically to respond to external environmental perturbations, and change their internal state as a result. Introducing controlled dynamical perturbations in minimal systems can provide insight into those processes. Currently, small biomolecular inducers are commonly used, yet applying these inducers locally and dynamically to compartmentalized micron-scaled reactions remains challenging. Here, we report on a DNA compartment fabricated in silicon and connected to thin electrodes, capable of external control of cell-free protein synthesis under steady-state conditions. We demonstrate manipulation of RNA polymerase, ribosomes and GFP in a nonuniform electrical field, using dielectrophoresis (DEP). We show local depletion of nutrients and machinery in an active gene expression reaction at physiologically relevant conditions. The response to the applied field is rapid at the scale of expression dynamics, and spatially confined thereby establishing spatiotemporal resolution of electric field control of gene expression.