Dynamic control of vapor diffusion protein crystal growth

Two laboratory based systems have been constructed to demonstrate methods which will allow for dynamic control of protein crystal growth. The technologies developed in these systems will be incorporated into future flight hardware for use in microgravity studies. The first system uses a precisely controlled vapor diffusion approach to monitor and control protein crystal growth. The system utilizes a humidity sensor and various interfaces under computer control to effect virtually any evaporation rate from up to 40 different growth solutions simultaneously. A second system utilizes the key features of the first system with the addition of a static laser light scattering sensor which can be used to detect aggregation events and trigger a change in the evaporation rate for a growth solution. This system also demonstrates that a Control/Follower configuration can be used to actively monitor one chamber and accurately control replicate chambers relative to the Control chamber. Results from experiments with both systems demonstrate that evaporation rate and dynamic control produce systematic effects on the size and number of crystals obtained. Both of these systems demonstrate significant advances in the ability of researchers to gain control of the protein crystal growth process and will provide tremendous opportunities for both terrestrial and microgravity research.