I-Corps: A freezable fluid cell for high-resolution cryo-electron microscopy

Brandeis University, Waltham MA

Investigators

Abstract

The broader impact and commercial potential of this I-Corps project are as follows: Cryo-Electron Microscopy (Cryo-EM) is a method for obtaining 3D structures of biological molecules. The method has growing importance in basic life science research and in the pharmaceutical sector for defining how drugs interact with their targets. Cryo-EM as a whole has matured into a powerful tool in recent years, culminating in the 2017 Nobel Prize in Chemistry, but the process of protein 'sample preparation' for 3D study has not advanced appreciably and is widely considered to represent the major bottleneck in the overall method. This bottleneck also presents a major commercial opportunity. The present project advances new nanofluidic-based technology aimed at addressing this bottleneck. Successful development of this technology will yield a consumable product ready for commercialization. Fulfillment of this goal will greatly advance and open new possibilities in cryo-EM structure determination. The resulting acceleration and enhancement of basic science and drug discovery would translate to broad societal benefit. This I-Corps project advances a new technology, supported by prototype data, to breach the major bottleneck in the rapidly growing cryo-EM field, with broad impact in life science and drug discovery. Cryo-EM is performed by taking images of frozen proteins using an electron microscope, then processing the images with a computer to obtain a 3D protein structure. To image and obtain a structure, the protein sample must first be frozen into a thin layer (~50-200 nm). With existing technology, this process is poorly controlled, lacks reproducibility and substantially adds to the time required to get a structure. Our device is designed to directly mitigate these sample preparation problems. It is a self-contained, freezable fluid cell nanofabricated to specification, giving full control over sample geometry and protein environment. Protein is passively loaded into the fluid cell, the loaded device is frozen, and can then be imaged directly. Materials on the top and bottom of the fluid cell are selected to transmit the electron beam through the protein sample with minimal noise. Successful prototype testing and data collection has shown the viability of the core design, with future work focused on refining the design and materials and streamlining manufacturing for eventual commercialization. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.