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Transmission Electron Microscopes

Krios G4 Cryo-TEM

Atomic resolution cryo-EM instrument with enhanced productivity and compact design.


The new award-winning Thermo Scientific Krios G4 Cryo-Transmission Electron Microscope (Cryo-TEM) enables you to unravel life at the molecular level—easier, faster, and more reliably than ever before. The most compact TEM in its class, the Krios G4 Cryo-TEM consists of a highly stable 300 kV TEM platform and the industry-leading Autoloader (a cryogenic sample manipulation robot), making it ideally suited for automated applications such as single-particle analysis (SPA)cryo-electron tomography (cryo-ET) and micro-electron diffraction (microED).

Through a thorough redesign of the mechanical base frame and system enclosure, the microscope height has been reduced to below 3 m, which allows for instrument installation in labs with a ceiling height below 3.04 m (~10 ft), preventing costly room renovations. Built-in connectivity ensures a robust and risk-free pathway throughout the entire workflow, from sample preparation and optimization to image acquisition and data processing.

Solve structures at record-breaking resolutions

Pair the Krios G4 Cryo-TEM with the Thermo Scientific E-CFEG and the groundbreaking Thermo Scientific Selectris and Selectris X Imaging Filters to advance cryo-EM discovery with unprecedented resolution, speed, and ease of use. 

The E-CFEG is a cold field emission gun with a narrow energy spread that results in higher contrast images and enables atomic resolution. This add-on makes it possible to efficiently solve structures at resolutions of 2.0 Å or less.

Selectris Imaging Filters provide unique stability, accessibility, and performance. Paired with the Thermo Scientific Falcon 4 Direct Electron Detector, these two add-ons produce better quality images up to 10 times faster than the previous generation.

An article published in Nature details how structural biologists used a Krios Cryo-TEM equipped with a Selectris Imaging Filter prototype to study protein structures at never-before-achieved resolutions, obtaining a 1.2 Å resolution structure of the iron-storing protein apoferritin and a 1.7 Å resolution of the GABA type A receptor-associated protein, with an even sharper resolution in key parts of the protein.

Already own a Krios Cryo-TEM? Explore upgrades and options ›

Benefits

Easier to fit into new or existing labs

Easier to fit into new or existing labs

Redesigned internal base frame and system enclosure reduce height below 3 m (10 ft) while enhancing system performance and preventing costly room renovations.

Atomic resolution performance

Atomic resolution performance

The optional Selectris X Imaging Filter with Falcon 4 Direct Electron Detector and E-CFEG cold field emission source improve image contrast to reach higher resolutions in shorter time.

Maximized productivity through software automation

Maximized productivity through software automation

Advanced Performance Monitoring ensures the best optical starting point for automated runs and EPU software enables automated grid screening, quality monitoring, and data management.

Workflow connectivity

Workflow connectivity

Designed for easy exchange of cassettes, facilitating a smooth transfer of specimens between Autoloader-equipped TEM instruments, and equipped with Athena Software to manage experimental parameters and data.

Key Features

See the throughput impact of the Falcon 4 Direct Electron Detector with 10 times shorter exposure times than previous generations.

Aberration-free image shift (AFIS) is an optical mode for faster data acquisition without comprising image quality. AFIS performs large beam shifts without off-axis coma and astigmatism.

Acquire more images per sample area with fringe-free imaging (FFI), enhancing your daily data throughput. Hear how FFI has been helping the daily research in the lab of Dr. Elizabeth Villa.

Make the most of your day with enhanced automation for acquisition setup, system remote monitoring to optimize microscope utilization, on-the-fly imaging with quality monitoring, and data management and project administration.

Upgrade options available for previous Krios Cryo-TEM generations

Electron Source

  • E-CFEG: Low-energy-spread cold field emission gun for higher contrast at truly atomic resolution

Detectors and Cameras

 

Software and Optical Modules

Krios Rx


Specifications

SourceX-FEG (extreme high-brightness field emission gun) or low-energy-spread cold FEG (E-CFEG)
Accelerating voltage80–300 kV
Cryo-AutoloaderAutomated and contamination-free loading of cassettes (up to 12 grids)
Temperature management softwareIncludes liquid nitrogen autofill and cool down scheduling
Lenses
  • Automatic condenser, objective and SA apertures
  • Three-condenser-lens system for automated, continuous, and parallel sample illumination
  • Symmetric constant power C-TWIN objective lens with wide-gap pole piece (11 mm) 
Stages
  • Computerized 4-axis specimen stage with ±70-degree alpha tilt
  • Cryo-stage with single axis holder for optimized stability and drift performance
ImagingRotation-free imaging with changing magnification
Advanced performance monitoringSelf-assessment of optical microscope status, combined with automated alignments, ensures ideal experimental conditions
Room Size Requirements (L × W × H)17’ × 22’ × 10’
AFIS (aberration-free image shift)Enhancing throughput with shorter relaxation times when moving coma-free between grid holes
FFI (fringe-free imaging)Enhanced throughput with multiple image acquisitions per grid hole
Thermo Scientific EPU 2 Software
  • Automated sample screening and data acquisition
  • EPU Multigrid functionality
Additional components
  • Three 24” monitors
  • Hand panels to be placed within 15 meters of the column, or extend up to 300 meters from the column (optional)
Detectors (optional)
  • Falcon 4 Direct Electron Detector
  • Thermo Scientific Ceta D Camera
  • Thermo Scientific Ceta 16M Camera
  • HAADF STEM detectors
  • On-axis BF/DF detectors
Energy filter (optional)
  • Selectris Imaging Filter
  • Selectris X Imaging Filter
  • Gatan BioContinuum Energy Filter 
Other options
  • Cs Image Corrector
  • Thermo Scientific Phase Plate Solution

Resources

Solve more structures more easily at higher resolution with the next-generation Thermo Scientific Krios G4 Cryo-TEM.

Cryo-EM: Introducing a New Krios TEM Solution­, presented by Dr. Marc Storms, Product Marketing Manager, Thermo Fisher Scientific.

Apoferritin is an iron-storing protein used to characterize cryo-EM performance. With the Selectris Imaging Filter, the position of individual hydrogen atoms, both in the protein and in surrounding water molecules, was resolved at 1.2 Å.

SARS-CoV-2 virion budding and assembly at the ERGIC membrane. A 3D volume rendering is shown with cellular and viral membranes in green and magenta respectively. Viral spike proteins are shown in yellow, and viral ribonucleoproteins in cyan. Courtesy of Chlanda lab, Schaller Research Groups, Department of Infectious Diseases, Virology, Heidelberg University, Heidelberg, Germany. Visualization by Amira software.

Discover more with our new publications search tool and subscribe to our monthly publications newsletter.

Learn more

Nakane, T., et al. Single-particle cryo-EM at atomic resolution. doi: 10.1038/s41586-020-2829-0

Abdella, R., et al. Structure of the human Mediator-bound transcription preinitiation complex. doi: 10.1126/science.abg3074

Zhou, Y., et al. Structure of a type IV CRISPR-Cas ribonucleoprotein complex. doi: 10.1016/j.isci.2021.102201

Su C.-C., et al. A 'Build and Retrieve' methodology to simultaneously solve cryo-EM structures of membrane proteins. doi: 10.1038/s41592-020-01021-2

Wigge, C., et al. The rapidly evolving role of cryo-EM in drug design. doi: 10.1016/j.ddtec.2020.12.003

Martynowycz, M.W., et al. MicroED structure of the human adenosine receptor determined from a single nanocrystal in LCP. doi: 10.1101/2020.09.27.316109

Zhang, X., et al. Differential GLP-1R Binding and Activation by Peptide and Non-peptide Agonists. doi: 10.1016/j.molcel.2020.09.020

Ma, J., et al. Structural basis of energy transfer in Porphyridium purpureum phycobilisome. doi: 10.1038/s41586-020-2020-7

Rougé, L., et al. Structure of CD20 in complex with the therapeutic monoclonal antibody rituximab. doi: 10.1126/science.aaz9356

Deniston, C.K., et al. Structure of LRRK2 in Parkinson's disease and model for microtubule interaction. doi: 10.1038/s41586-020-2673-2

Wang, L., et al. Purification and cryoelectron microscopy structure determination of human V-ATPase. doi: 10.1016/j.xpro.2021.100350

Josephs, T.M., et al. Structure and dynamics of the CGRP receptor in apo and peptide-bound forms. doi: 10.1126/science.abf7258

Thermo Scientific Krios Cryo-TEM publications
Thermo Scientific Krios Cryo-TEM publications associated with released maps. Source: EMDB database Jan 20, 2021.

Solve more structures more easily at higher resolution with the next-generation Thermo Scientific Krios G4 Cryo-TEM.

Cryo-EM: Introducing a New Krios TEM Solution­, presented by Dr. Marc Storms, Product Marketing Manager, Thermo Fisher Scientific.

Apoferritin is an iron-storing protein used to characterize cryo-EM performance. With the Selectris Imaging Filter, the position of individual hydrogen atoms, both in the protein and in surrounding water molecules, was resolved at 1.2 Å.

SARS-CoV-2 virion budding and assembly at the ERGIC membrane. A 3D volume rendering is shown with cellular and viral membranes in green and magenta respectively. Viral spike proteins are shown in yellow, and viral ribonucleoproteins in cyan. Courtesy of Chlanda lab, Schaller Research Groups, Department of Infectious Diseases, Virology, Heidelberg University, Heidelberg, Germany. Visualization by Amira software.

Discover more with our new publications search tool and subscribe to our monthly publications newsletter.

Learn more

Nakane, T., et al. Single-particle cryo-EM at atomic resolution. doi: 10.1038/s41586-020-2829-0

Abdella, R., et al. Structure of the human Mediator-bound transcription preinitiation complex. doi: 10.1126/science.abg3074

Zhou, Y., et al. Structure of a type IV CRISPR-Cas ribonucleoprotein complex. doi: 10.1016/j.isci.2021.102201

Su C.-C., et al. A 'Build and Retrieve' methodology to simultaneously solve cryo-EM structures of membrane proteins. doi: 10.1038/s41592-020-01021-2

Wigge, C., et al. The rapidly evolving role of cryo-EM in drug design. doi: 10.1016/j.ddtec.2020.12.003

Martynowycz, M.W., et al. MicroED structure of the human adenosine receptor determined from a single nanocrystal in LCP. doi: 10.1101/2020.09.27.316109

Zhang, X., et al. Differential GLP-1R Binding and Activation by Peptide and Non-peptide Agonists. doi: 10.1016/j.molcel.2020.09.020

Ma, J., et al. Structural basis of energy transfer in Porphyridium purpureum phycobilisome. doi: 10.1038/s41586-020-2020-7

Rougé, L., et al. Structure of CD20 in complex with the therapeutic monoclonal antibody rituximab. doi: 10.1126/science.aaz9356

Deniston, C.K., et al. Structure of LRRK2 in Parkinson's disease and model for microtubule interaction. doi: 10.1038/s41586-020-2673-2

Wang, L., et al. Purification and cryoelectron microscopy structure determination of human V-ATPase. doi: 10.1016/j.xpro.2021.100350

Josephs, T.M., et al. Structure and dynamics of the CGRP receptor in apo and peptide-bound forms. doi: 10.1126/science.abf7258

Thermo Scientific Krios Cryo-TEM publications
Thermo Scientific Krios Cryo-TEM publications associated with released maps. Source: EMDB database Jan 20, 2021.

Applications

Life_Sciences_Application_274x180_144DPI

Structural Biology Research

Cryo-electron microscopy enables the structural analysis of challenging biological targets such as large complexes, flexible species and membrane protein.

DrugDiscovery_Appl_274x180

Drug Discovery

Learn how to take advantage of rational drug design for many more major drug target classes, leading to best-in-class drugs.

Infectious_Disease_Research_App_w274x180

Infectious Disease Research

Cryo-EM techniques enable multiscale observations of 3D biological structures in their near-native states, informing faster, more efficient development of therapeutics.

Techniques

Single Particle Analysis

Single particle analysis (SPA) is a cryo-electron microscopy technique that enables structural characterization at near-atomic resolutions, unraveling dynamic biological processes and the structure of biomolecular complexes/assemblies.

Learn more ›

Cryo-Tomography

Cryo-electron tomography (cryo-ET) delivers both structural information about individual proteins as well as their spatial arrangements within the cell. This makes it a truly unique technique and also explains why the method has such an enormous potential for cell biology. Cryo-ET can bridge the gap between light microscopy and near-atomic-resolution techniques like single-particle analysis.

Learn more ›

MicroED

MicroED is an exciting new technique with applications in the structural determination of small molecules and protein. With this method, atomic details can be extracted from individual nanocrystals (<200 nm in size), even in a heterogeneous mixture.

Learn more ›

Single Particle Analysis

Single particle analysis (SPA) is a cryo-electron microscopy technique that enables structural characterization at near-atomic resolutions, unraveling dynamic biological processes and the structure of biomolecular complexes/assemblies.

Learn more ›

Cryo-Tomography

Cryo-electron tomography (cryo-ET) delivers both structural information about individual proteins as well as their spatial arrangements within the cell. This makes it a truly unique technique and also explains why the method has such an enormous potential for cell biology. Cryo-ET can bridge the gap between light microscopy and near-atomic-resolution techniques like single-particle analysis.

Learn more ›

MicroED

MicroED is an exciting new technique with applications in the structural determination of small molecules and protein. With this method, atomic details can be extracted from individual nanocrystals (<200 nm in size), even in a heterogeneous mixture.

Learn more ›


Contact us

Electron microscopy services for
the life sciences

To ensure optimal system performance, we provide you access to a world-class network of field service experts, technical support, and certified spare parts.

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