A magnetic field and high-pressure are effective parameters to control protein crystallization. A magnetic field significantly affects the number, orientation and growth rate (morphology) of protein crystals and damps the buoyancy convection in protein solutions. Quality of protein crystals can be also improved by a magnetic field. The improvement in the crystal quality is due to a magnetic orientation effect. High-pressure can also give large effects on the solubility and growth kinetics of protein crystals. Changes in the solubility with pressure results from a difference in the volume between bulk water and the water hydrating the contact regions of protein molecules inside the crystal.
