Cryo-electron microscopy

Cryo-electron microscopy
Hiramano92 · CC BY-SA 4.0 · source
Name	Cryo-electron microscopy
Invented	1980s–2010s
Inventors	Jacques Dubochet, Richard Henderson, Joachim Frank
Field	Structural biology

Cryo-electron microscopy is a technique for imaging biological macromolecules, complexes, and assemblies at near-atomic resolution by combining rapid freezing, transmission electron microscopy, and computational reconstruction. It enabled structure determination of viruses, ribosomes, ion channels, and large protein complexes implicated in human disease, and earned Jacques Dubochet, Richard Henderson, and Joachim Frank major recognition for methodological breakthroughs. Laboratories at institutions such as MRC Laboratory of Molecular Biology, Max Planck Society, and National Institutes of Health have been central to its development and dissemination.

Introduction

Cryo-electron microscopy integrates concepts developed in laboratories including the MRC Laboratory of Molecular Biology, the European Molecular Biology Laboratory, and the National Center for Electron Microscopy to image specimens preserved in vitreous ice. Key figures associated with early breakthroughs include Jacques Dubochet, Joachim Frank, and Richard Henderson, whose work intersected with groups at Columbia University, University of Cambridge, and Harvard University. The technique complements established methods such as X-ray crystallography and nuclear magnetic resonance spectroscopy, and has been applied by researchers at institutions like Stanford University, Massachusetts Institute of Technology, and University of Oxford.

Principles and Techniques

Cryogenic preservation relies on rapid vitrification first demonstrated by researchers connected to European Molecular Biology Laboratory, influenced by protocols from Max Planck Institute for Biophysical Chemistry and early electron optics developed at Bell Laboratories. Imaging uses transmission electron microscopes whose optics trace back to work at University of Cambridge and Caltech. Single-particle analysis workflows adopted algorithms from groups at Princeton University, Yale University, and Columbia University. Tomographic methods draw on computational geometry advances from Massachusetts Institute of Technology and Stanford University, while phase plate approaches were pioneered in collaborations involving National Institutes of Health and MPI for Medical Research.

Instrumentation and Sample Preparation

High-end microscopes commonly used in the field were produced by companies associated with commercialization efforts involving Thermo Fisher Scientific and JEOL Limited, and often installed in facilities at Brookhaven National Laboratory and Lawrence Berkeley National Laboratory. Key hardware includes direct electron detectors developed following research allied to University of California, San Diego and University of Colorado Boulder, energy filters influenced by teams at Argonne National Laboratory, and cryo-stages refined through work at European Synchrotron Radiation Facility and DESY. Sample vitrification equipment traces to protocols taught at Cold Spring Harbor Laboratory, while grid technologies evolved in collaborations with NIH Cryo-EM Facility and EMBL Hamburg.

Image Processing and Reconstruction

Image processing pipelines rely on software frameworks shaped by developers at Max Planck Institute for Biophysical Chemistry, University of Oxford, and Harvard Medical School. Algorithms for particle alignment and classification were advanced by groups at Princeton University, ETH Zurich, and University of California, San Francisco. Maximum-likelihood and Bayesian approaches incorporated insights from statisticians at University of Cambridge and Imperial College London, while machine learning integration has seen contributions from researchers at Google DeepMind, University College London, and ETH Zurich. Cryo-electron tomography reconstruction workflows benefit from mathematical tools developed at Caltech and Carnegie Mellon University.

Applications

Cryo-EM has resolved structures of the ribosome studied by teams at Cold Spring Harbor Laboratory and University of Cambridge, viral capsids analyzed by groups at Rockefeller University and Pasteur Institute, and membrane proteins such as ion channels from laboratories at Columbia University and Scripps Research. Pharmaceutical research at Pfizer and Roche uses cryo-EM for drug-target validation; structural immunology projects at Baylor College of Medicine and Johns Hopkins University exploit it to study antibody–antigen complexes. Studies of respiratory complexes have been conducted by researchers at Max Planck Institute for Biochemistry and University of California, Berkeley, while plant and microbial complexes have been imaged by groups at ETH Zurich and University of Tokyo.

Advantages and Limitations

Advantages emphasized in reports from MRC Laboratory of Molecular Biology and NIH include ability to image heterogeneous populations, reduce need for crystallization compared with X-ray crystallography labs at Brookhaven National Laboratory, and capture multiple conformational states as done by teams at Harvard University and Stanford University. Limitations include beam-induced motion challenges identified by researchers at Lawrence Berkeley National Laboratory, radiation damage constraints studied at Argonne National Laboratory, and sample-preparation artifacts investigated at Cold Spring Harbor Laboratory and EMBL Heidelberg. Accessibility and cost issues are topics at institutions such as University of California, San Francisco and national facilities like eBIC.

History and Development

Foundational theoretical and practical work was contributed by scientists at MRC Laboratory of Molecular Biology, Max Planck Society, and Columbia University through the late 20th century, with seminal contributions by Joachim Frank on image processing, by Jacques Dubochet on vitrification, and by Richard Henderson on achieving high-resolution structures. Commercialization and technological refinement accelerated in the 2000s with involvement from Thermo Fisher Scientific and detector innovation influenced by research at University of California, San Diego. Major milestones include ribosome structures resolved by groups at Rockefeller University and University of Cambridge, membrane protein structures from Scripps Research, and the awarding of high-profile prizes recognizing innovators affiliated with MRC Laboratory of Molecular Biology and Max Planck Institute for Biophysical Chemistry.

Category:Electron microscopy