Protein Crystallization in Microdroplets with the Aid of Electrically Induced Microbubbles

We present a novel concept of microfluidic system that enable promoting the protein crystal nucleation, monitoring the protein crystallization state, and analysis the crystal structure in a sequential process. This proposed system comprised of four main functional parts: (i) the protein crystal nucleation using an electrically induced microbubble injector, (ii) droplets generation by microchannel, (iii) monitoring of a crystal morphology in droplets to optimize their incubation time, (iv) sorting of droplets containing produced crystals suitable for X-ray crystallography and analyzing the protein structure. As the first step of this research, in this study, we developed a critical functional part of the concept that enable control of the protein crystallization and could confirm the mean number of protein crystal in droplets, which was treated by electrically induced bubble, increased approximately 1.5 times as compared with that of protein crystal in untreated droplets.