Membrane-Based Micro-Volume Dialysis Method for Rapid and High-Throughput Protein Crystallization

Protein crystallization techniques are very important in drug development. This paper discusses a membrane-based micro-volume dialysis method suitable for rapid and high-throughput protein crystallization. A droplet of protein solution was deposited on the membrane surface in a micro-volume dialysis device. Crystallizing agents could be added to the protein solution either directly or through the membrane. The crystallization process could easily be monitored in real time under a microscope. Tiny specks, indicative of forming crystals, were observed as early as 30 s from the start of the experiment, and these were clearly distinguishable as tetragonal lysozyme crystals within 2 min. This method is particularly suitable for carrying out screening and optimization experiments, and for studying crystallization kinetics. The easy and direct manner in which protein and crystallizing agents are introduced into the device makes this method amenable to miniaturization and automation. Additionally, this approach would potentially allow for rapid screening of the effects of drug molecules on the crystallization process and the nature of crystal formation.