ac field enhanced protein crystallization

Uniform and nonuniform ac electric fields sustained by internal microfabricated electrodes are shown to sensitively affect protein crystallization by reducing the number of nucleation sites and enhancing the quality of the crystals formed. Under conditions when massive spontaneous nucleation occurs, a properly tuned ac field can desolvate the protein molecules to form a gel matrix with only a few nucleation sites. A dielectrophoretic force generated by the nonuniform ac field further consolidates these crystallites. Upon field removal, the gel transforms into crystals around these nucleation sites to form high-quality large crystals.