Microfluidic Technologies and Platforms for Protein Crystallography

Protein crystallization and three-dimensional structural analysis are indispensable for understanding protein functions in the body and other biological phenomena. Three-dimensional protein structure also plays an important role in drug discovery and has already been used to design new drugs. To determine the three-dimensional protein structure, protein crystallization conditions, such as protein concentration, precipitant type and concentration, buffer, pH, temperature, and additives, must be optimized. In addition, high-diffraction-quality protein crystals are required to determine the three-dimensional protein structure at a high resolution. However, optimization of protein crystallization conditions and preparation of high-quality protein crystals is labor intensive and requires trial and error. Thus, microfluidics provides a solution for the problems associated with traditional protein crystallography. Many microfluidic-based technologies and platforms have been developed to exploit the unique characteristics of microfluidics. This chapter summarizes microfluidic technologies and platforms for protein crystallography. In particular, the applications of microfluidics for high-throughput screening of protein crystallization conditions, control of protein crystal growth, and on-chip X-ray diffraction experiments using microfluidic devices are reviewed.