Electron Optic Documents

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-EM has enjoyed an enormous ground swell in popularity ever since the advent of more stable and automated electron microscopes, suitable movie-type cameras, and improved acquisition software. Results obtained so far have been nothing short of spectacular as illustrated by several structures in EMDB and EMPIAR solved by cryo-EM to resolutions better than 1.5Å, such as EMD-31314, EMD-33707 and EMD-35984, the latter of which reaching true atomic resolution. This note describes screening of cryo-EM samples on a JEOL JEM-1400Flash with a Gatan ELSA holder before committing to an SPA run on higher-end electron cryo-microscopes, such as the JEOL CRYO ARM.

“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.

The Electrostatic Dose Modulator (EDM) is a fast beam blanking system with a pre-sample electrostatic deflector that includes electronics and software control. With EDM, the beam can switch on or off in less than 50 ns. This 100,000x improvement in blanking speed results in immediate enhancement in the clarity of data taken at fast exposure times. Moreover, EDM includes a desktop control knob that allows users to easily attenuate electron dose without affecting imaging conditions. The included software interface gives TEM and STEM users direct access to EDM’s pulse width modulation parameters providing exceptional control over the dose rate on their samples – invaluable feature for beam sensitive specimen imaging and analysis.

The applications for lithium ion batteries (LIB) cover a wide range, from power sources for personal computers and mobile devices to automobiles, and there is always a demand for even better performance and safety. In order to ensure the performance and quality of LIB, analysis and evaluation using high-performance assessment systems is necessary. JEOL offers a full line-up of equipment to support the development of new LIB technologies and to improve product quality, including instruments for morphology observation and surface analysis, chemical analysis systems to perform structural analysis on a molecular level, as well as fabrication systems to create high-performance coatings and powders. This LIB note offers solutions for researchers and engineers who are looking for the best equipment for their application.

Luminary Micro is a Compact Specimen Photoexcitation System (CPXS) for JEOL TEMs. It is composed of a modulated laser, a compact optical delivery system, an inlet port, and a mirror. With this add-on, users can direct and focus the laser output onto the TEM sample in situ. Luminary Micro can induce a rich variety of reactions and dynamic processes in the specimen, thanks to its <40 μm FWHM focus size, adjustable peak power up to 3 W, and the modulated pulse widths ranging from a few microseconds to seconds. With Luminary Micro, users can study laser-induced phenomena in situ using fast cameras. Combined with IDES/JEOL EDM fast shutter and/or Relativity subframing systems, Luminary Micro allows users to perform time-resolved studies using pump-probe methods in the microsecond time scale. The extremely compact footprint of the system allows easy installation without affecting the TEM resolution. The user can heat specimens to thousands of degrees C while keeping the freedom to use the specimen holder of your choice.

The IDES Relativity Electrostatic Subframing System multiplies the frame rate of cameras on JEOL TEMs. Microscopes equipped with Relativity achieve exceptional time resolution, data throughput, and advanced automation capabilities. Addition of Relativity allows current JEOL TEM users to forego expensive camera upgrades to their existing systems, instead relying on installation of an electrostatic optics assembly in a wide-angle camera port. These optics rapidly deflect the image data to different regions (subframes) of the camera in a programmable sequence. Each camera readout contains a tiled array of crisp, blur-free subframes. Raw data is automatically analyzed to give a stack of open format images that are loaded back into the camera control software for viewing or further analysis.