Visualization of protein crystal growth inside hanging-drop reactors of the Advanced Protein Crystallization Facility

The Advanced Protein Crystallization Facility is widely used by European and US teams to study protein crystal growth under microgravity conditions. This paper describes the laboratory equipment developed to observe the crystals, by means of a charge-coupled-device camera, during the growth process on the ground inside the hanging-drop reactors of the Advanced Protein Crystallization Facility. The apparatus was used during ground tests performed to prepare the microgravity experimentation, allowing a time reduction in determining the crystallization conditions to be used for the microgravity experiment.