Cell-free protein expression from DNA-based hydrogel (P-Gel) droplets for scale-up production

This paper presents a promising potential scale-up method for cell-free protein production that integrates microfluidic devices and DNA-based hydrogels (P-gels). The microfluidic devices were fabricated using established photolithography techniques. The P-gels were formed via enzymatic ligation of branched DNA nanostructures with genes. More specifically, the microfluidic devices contained droplet-forming junctions through which numerous micron-sized P-gel droplets were produced. The advantages of our microfluidic-based approach include highly controlled fluid manipulation, rapid droplet generation, high reproducibility, and low sample consumption. P-gel droplets successfully expressed green fluorescent protein (GFP) in high yield, and the microfluidic devices achieved a variety of P-gel droplet sizes while maintaining uniform morphology and a high generation rate. We envision that our system could provide a cell-free platform for both high-throughput and scale-up production of multiple proteins.