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Documents of interest in support of your JEOL product

Atomic resolution structure results from the JEOL 200 kV CRYO ARM™ TEM

High resolution structure determination by electron cryo-microscopy (cryoEM) and Single Particle Analysis (SPA) has progressed to the point where structures can be determined routinely to better than 3Å on a 300 kV microscope. Pioneering efforts have shown that similar results can also be achieved on 200 kV platforms. Similarly, efforts are underway to allow for a structure determination within a single day or even less. Here, we show results from Merk et al. at NIH from the JEOL CRYO ARM™ 200 obtained on beta-galactosidase at 1.8Å resolution1. The 3D map shows surprising details in the map reflecting the high resolution quality of the data.

Atomic resolution structures of biological macromolecules using microED on JEOL TEMs

Micro electron diffraction, or microED, is a technique aimed at solving structures of biological macromolecules by electron diffraction. Barn-storming work by the group from Prof. Gonen showed the impressive impact and promise of this technique1. The technique borrows from X-ray crystallography in that precession techniques are used for data collection and that much of the well-established software for solving structures by X-ray crystallography can be used for microED. However, it differs in a fundamental way in that electrons are used, which, owing to the substantially larger scattering cross-section of electrons with biological matter, means much smaller crystals can be used.

CRYO ARM™ series microscopes for cryo-EM in structural analysis of proteins and viruses

Cryo-EM has seen an enormous increase in capabilities and potential in recent years owing to a number of technological advances, e.g. direct detector devices and improved scope automation. JEOL released two electron cryo-microscopes in 2017 specifically designed for automated and unattended, continuous operation at 200 and 300 kV, the CRYO ARM™ series. A recent update on both type of CRYO ARMs has the potential of increasing the throughput well beyond the current limit of 20,000 images/day, namely north of 50,000 images/day as well as extending the resolution to nearly true atomic resolution, i.e. 1.2Å.

CryoNote

“Visualize the truth” is a hope of researchers who use various measuring equipment. Researchers who use electron microscopes as well have a desire to observe the real structure. But actually, in experiments using electron microscopes, many problems arise: They include damage regions of the specimen when it is cut for the size suited to observation, artifacts due to the staining that is applied to enhance image contrast, deformation caused by substitution of water to resin for withstanding vacuum exposure, and thermal damage to the specimen with electron-beam irradiation. As a result, the visualization of the real structure in the microscope image becomes increasingly difficult. One recommended solution is to cool the specimen, that is, “Cryo” techniques. This “Cryo Note” introduces some of the diversified cryo-techniques. We sincerely hope your challenge to observe the “real structure” will be solved by “Cryo” methods.

F2: 3D Tomography

The F2 is a new concept of 20-200kV TEM equipped with a Cold FEG. This new generation of multi-purpose electron microscope is designed specifically to meet today’s diversified needs. Transmission electron microscopy gives access to two-dimensional information coming from the sample. The third dimension is available thanks to the tomography technique. The sample is tilted and for each step, an image (TEM, STEM, EDS) is acquired. Then the 3D volume of the sample can be reconstructed. The F2 has a “Dual SDD system”, which is composed of two silicon drift detectors (SDD) with large sensor areas, resulting in a total solid angle of 1.7 sr. The combination of two detectors and their placement around the sample, allows the ability to record EDS information throughout the full tilt series (from -80° to +80°).

F2: EDS - Double Your Capabilities

The F2 is a new concept of 20-200kV TEM equipped with a Cold FEG. This new generation of multi-purpose electron microscope is designed specifically to meet today’s diversified needs. Thanks to the high brightness and small probe size of the Cold FEG, the F2 is able to reach an unprecedented guaranteed resolution for STEM (0.14nm), EDS (1.7sr) and EELS (0.3eV) at the same time, creating a new class of high-end non-corrected TEM.

Other Resources

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  • Links & Resources
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