(148d) Scalable Manufacturing of X-Ray Compatible Microfluidics for High-Throughput Structure Determination and Integrated Liquid Handling Strategies

Silicone-based elastomers, along with thermoplastics and paper, represent the most widely used materials for microfluidic devices. However, applications in structural biology require a level of X-ray transparency that is difficult to achieve with traditional materials. A key aspect of protein structure determination is the manual harvesting and freezing of protein crystals, which are analyzed by X-ray diffraction to resolve the final 3D structure. Here we demonstrate the use of UV-curable polymers that have good X-ray transparency and further allow for automated sample loading towards high-throughput and/or remote X-ray data collection. We additionally showcase continuous manufacturing of these devices to enable more cost-effective large-scale manufacturing that is 80 times faster than traditional batch fabrication strategies and thus reduce labor costs significantly.

We leverage this approach to develop microfluidic devices that allow for on-chip crystallization and structure determination. The reagent manipulation requirements for crystallization experiments calls for precise liquid handling strategies and therefore incorporation of a novel valving mechanism compatible within the UV-curable device architecture. Our design incorporates advanced fluid handling systems, realized through both centrifugal and electrically actuated valves, departing from conventional pressure-driven systems typically associated with cumbersome equipment like pneumatic controllers and nitrogen cylinders. Our devices provide a one-step solution for structural biologists, from screening crystallization conditions to determining the protein structure. These capabilities in a microfluidic device also have the potential to enable next generation structural biology experiments, like ligand binding and time-resolved experiments, while bringing us one step closer to automating the labor-intense process of crystallization and crystallography.