Miniaturized fluid array for high-throughput protein expression

We describe a miniaturized fluid array device for high-throughput cell-free protein synthesis (CFPS), aiming to match the throughput and scale of gene discovery. Current practice of using E. coli cells for production of recombinant proteins is difficult and cost-prohibitive to implement in a high-throughput format. As more and more new genes are being identified, there is a considerable need to have high-throughput methods to produce a large number of proteins for studying structures and functions of the corresponding genes. The device consists of 96 units and each unit is for expression of one protein; thus up to 96 proteins can be produced simultaneously. The function of the fluid array was demonstrated by expression of a variety of proteins, with more than two orders of magnitude reduction in reagent consumption compared with a commercially available CFPS instrument. The protein expression yield in the device was up to 87 times higher for β-glucoronidase than that in a conventional microplate. The concentration of β-galactosidase expressed in the device was determined at 5.5 μg/μL. The feasibility of using the device for drug screening was demonstrated by measuring the inhibitory effects of mock drug compounds on synthesized β-lactamase without the need for harvesting proteins, which enabled us to reduce the analysis time from days to hours.