Thermo Scientific Krios 5 Cryo-Transmission Electron Microscope

Overview

The Thermo Scientific™ Krios⁵ Cryo-Transmission Electron Microscope (Cryo-TEM) is an advanced, high-stability platform engineered for atomic-resolution structural biology workflows—including single-particle analysis (SPA), cryo-electron tomography (Cryo-ET), and microcrystal electron diffraction (MicroED). Operating at liquid nitrogen or liquid helium temperatures, the system maintains specimen integrity in vitrified ice while enabling high-fidelity imaging under ultra-high vacuum. Its column architecture integrates a field-emission gun (FEG), monochromated electron source, and aberration-corrected optics to minimize chromatic and spherical aberrations—critical for achieving sub-2 Å resolution in dose-efficient acquisition modes. Designed for reproducible, high-throughput data collection, the Krios⁵ serves as a central instrument in structural proteomics, membrane protein characterization, and integrative structural biology pipelines aligned with international standards including ISO/IEC 17025 for analytical laboratory competence.

Key Features

• Enhanced automated alignment routines reducing setup time and operator dependency across daily operation cycles
• Improved optical stability and beam coherence via upgraded lens excitation control and thermal shielding
• AI-assisted Smart EPU software suite with real-time particle picking, drift correction, and classification feedback loops
• Extended Aberration-Free Image Shift (AFIS) range supporting multi-position acquisition without mechanical stage repositioning
• Sub-1% magnification calibration accuracy validated per ASTM E1874–22 for TEM scale calibration protocols
• Integrated EER (Electron Event Representation) 8K sensor decoding enabling Nyquist-exceeding frame rates and motion-corrected movie stacks
• Vacuum-sealed transfer capsule compatible with Thermo Scientific Arctis™ Cryo-FIB Plasma FIB systems for site-specific lamella preparation
• Eco Mode power management with rapid wake-up scheduling and energy consumption monitoring compliant with My Green Lab® ACT® Ecolabel criteria

Sample Compatibility & Compliance

The Krios⁵ accommodates standard 3 mm TEM grids (including Quantifoil, UltrAuFoil, and graphene oxide variants) mounted in Gatan 626/914 cryo-holders or newer auto-loading systems. It supports both plunge-frozen and high-pressure frozen specimens, with compatibility verified against USP General Chapter <1117> for cryo-EM sample handling best practices. System-level compliance includes adherence to IEC 61000-6-3 (EMC emissions), IEC 61000-6-2 (immunity), and CE marking for laboratory instrumentation. Audit-ready logging features satisfy GLP/GMP documentation requirements, including timestamped metadata capture for every image series, aligning with FDA 21 CFR Part 11 electronic record integrity guidelines.

Software & Data Management

Data acquisition and processing are unified through Thermo Scientific™ CryoFlow™ software, which orchestrates workflow automation from grid screening to tilt-series collection. Discovery Viewer provides intuitive navigation of large-scale cryo-ET datasets, while Tomography 5 enables robust alignment, denoising, and reconstruction using iterative weighted back-projection and SIRT algorithms. All raw and processed data are stored in standardized HDF5 containers with embedded metadata conforming to EMDB and PDBx/mmCIF schema conventions. The system supports secure integration with institutional LIMS and cloud-based storage via DICOM-EM extensions, ensuring FAIR (Findable, Accessible, Interoperable, Reusable) data principles throughout the research lifecycle.

Applications

• Atomic-resolution structure determination of macromolecular complexes via single-particle cryo-EM
• In situ structural analysis of cellular organelles and subcellular structures using cryo-electron tomography
• Three-dimensional reconstruction of heterogeneous samples, including membrane proteins in native lipid environments
• MicroED-based structure solution of nanocrystalline pharmaceutical compounds and small-molecule APIs
• Time-resolved cryo-EM studies enabled by rapid grid loading and synchronized shutter control
• Correlative light and electron microscopy (CLEM) workflows integrated via modular fluorescence stages

FAQ

Is the Krios⁵ manufactured in the United States?
No—the Krios⁵ system referenced here is assembled and qualified at Thermo Fisher’s Shanghai manufacturing facility, meeting global quality system requirements under ISO 13485 and ISO 9001 certification scopes.
Does this configuration support remote operation and monitoring?
Yes—full remote access is enabled via secure TLS-encrypted VNC and web-based CryoFlow dashboard interfaces, with role-based permissions aligned with institutional IT security policies.
What level of service and support is available for domestic users in China?
Thermo Fisher provides localized application support, preventive maintenance contracts, and on-site engineering services through authorized distribution partners certified under Thermo Fisher Service Excellence Program (SEP) standards.
Can the Krios⁵ be upgraded to include energy-filtered TEM (EFTEM) capabilities?
While the base Krios⁵ configuration does not include a post-column energy filter, optional integration with Gatan Imaging Filter (GIF) systems is supported through factory-installed ports and software synchronization modules.
How is calibration traceability maintained for quantitative measurements?
All magnification, defocus, and pixel size calibrations are traceable to NIST-traceable reference standards (e.g., Au/Pt lattice fringes, amorphous carbon thickness standards), with calibration logs archived alongside raw data in accordance with ISO/IEC 17025 clause 7.7.