Unattended, High Throughput Cryo-TEM

JEOL announces the latest member in its family of high-end transmission electron microscopes, the CryoARM. This highly automated TEM is designed for unattended operation and high throughput imaging of cryo-EM specimens. The CryoARM was initially introduced to a select audience at the 2016 Gordon Research Conference in Hong Kong, M&M 2016 in Columbus, OH and EMC 2016 in Lyon, France.

The CryoARM is a dedicated cryo-TEM, based on the highly successful JEOL ARM (Atomic Resolution Microscope) series, an ultrahigh performance, highly stable platform considered to be the "best-in-class" TEM. The development of the CryoARM was accomplished in collaboration with leading Life Science researchers.

Cold FEG Option for Improved Contrast Transfer

Unique for Life Science applications is the option of a Cold Field Emission Gun (cFEG). With its significantly smaller energy spread as compared to traditional thermal field emission sources, the cFEG provides a significant boost in image contrast owing to an improvement in the envelope functions, particularly in the sub-5Å resolution region. The Flash-and-Go technology from JEOL that is now incorporated into the ARM family of microscopes makes the cFEG for Life Science a reality.

Parallel Beam Conditions at Any Beam Diameter

Paramount in obtaining high resolution images of cryo samples is the ability to set parallel beam conditions for the illumination. The CryoARM features three condenser lenses to enable this condition. JEOL was the first to use this technology in the 1980s to enable TEM and STEM imaging on a single platform. The illumination angle of the beam, also known as the alpha angle, can be preset to specific values depending on the magnification, or to any value using a Free Lens Control program, thus allowing for parallel beam condition at any beam diameter.

Enhanced Image Contrast

The in-column Omega energy filter, unique to JEOL TEMs, provides a substantial boost in image contrast by removing inelastically scattered electrons. Placement within the column gives the operator complete flexibility in the choice of camera. A key benefit of the in-column filter is its higher stability compared to post-column configurations. The Omega filter provides for a critical mechanism to obtain high-resolution images and diffraction intensities unaffected by inelastic scattering, the latter of which is critically important for a relatively new technique in cryo-EM known as microED (the use of electron diffraction data similarly as in xray precession diffraction techniques to elucidate biological structures).

A second method for substantial improvement in the image contrast is through the use of Hole Free Phase Plates (HFPP). Manufacturing of the phase plates employs a unique approach resulting in robust and reliable performance at reasonable prices.

Unattended, high throughput imaging

The CryoARM's data collection process can be controlled by several well-known software tools, e.g., JADAS, Leginon or SerialEM, each of which has been interfaced to a variety of direct detection cameras.