A principal hypothesis of our research is that the properties of detergent and protein/detergent solutions, such as their phase behavior and critical phenomena, play a significant role during membrane protein crystallization. Therefore, the characterization of these properties, and the subsequent incorporation of this information into crystallization experiments, will enable the more successful formation of well-ordered membrane protein crystals for structure determination. We are utilizing a variety of techniques for the development and implementation of detergent-specific membrane protein crystallization screens. Observation of dye partitioning in detergent/solute mixtures enables the relatively rapid determination of phase boundaries, and this information is utilized in the design of crystallization screens that are currently being tested. A commercial crystallization robot has been modified for use in the in situ setup of crystallization screens. Lastly, the characterization of critical phenomena in detergent solutions has been initiated.