Electron Optic Documents

Tomography is a technique that employs a series of images successively recorded from an object at different tilt angles with respect to the electron beam in order to obtain that object’s three-dimensional structure using a back projection technique. The images can be recorded in a Transmission Electron Microscope (TEM) or a Scanning Transmission Electron Microscope (STEM). JEOL have adopted SerialEM (Boulder laboratory for 3D electron microscopy of cells BL3DEMC) to either modality making tomography an accessible, efficient and easy technique for all aspects of scientific, industrial and medical research.

As seen in IUCrJ Volume 7, July 2020, pages 639-643.

TEM phase plate development was extensively pursued by Prof Nagayama’s lab in Japan for over ten years. Prof Chiu of Baylor College of Medicine has successfully applied the phase plate system on his Omega filtered TEM (JEM-2200FS) to the molecular structure characterization for proteins.

Auto Tuning for HR-STEM for crystalline sample.

A solid-state battery is made of cathode, anode and electrolyte. This type of battery doesn’t use liquid state electrolyte, so it tends to avoid the issues associated with leakage of electrolyte and ignition/explosion. Recently, silicon has been used as an anode material to improve the battery charge capacity (can store ten times more charge as compared to graphite anodes), but some challenges remain in terms of volume expansion during cycling, low electrical conductivity, and instability of the SEI (solid electrolyte interphase) layer caused by repeated volume changes of the Si material.

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.

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 2Å on a 300 kV microscope. Here, we show results from Kato et al. at1 Osaka University from the JEOL CRYO ARM™ 300 installed at SPring8 (Riken, Japan), that was obtained on mouse heavy chain apo-ferritin at 1.5Å resolution. The 3D map shows surprising details in the map reflecting the high resolution quality of the data.

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 Bibliography

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.