Methods

4D STEM involves acquiring a 2D convergent beam electron diffraction (CBED) pattern, at every pixel of a 2D STEM raster, generating a 4D dataset containing momentum and spatial information about the specimen. The key advantage of 4D STEM compared to conventional 2D STEM imaging…

With the exception of the environmental SEM, liquid water cannot be observed in the SEM due to the high vacuum in the microscope’s column. Due to this limitation, most aqueous samples, biological or synthetic, are observed in the SEM only after the application of chemical…

Sequential cyclic removal of nanometric layers from the sample block face and the SEM image acquisition of each newly produced surface. In this manner, hundreds to several thousand of SEM images can be collected in automatic regime, and then processed to generate 3D dataset of…

For ultrastructural analysis of biological specimens such as various tissues, cells (suspension and cell monolayers), bacteria or plants, the biological sample is stabilized by immersion in a mixture of chemicals containing Glutaraldehyde and formaldehyde. Glutaraldehyde reacts…

FIB patterning is a milling technique to engrave a surface with submicrometer size features, typically tens to several hundred nanometers.

X-ray tomography is ideally suitable for non-destructive three-dimensional visualization and analysis of a wide range of samples, from biological tissues to synthetic materials. Tomographic datasets are obtained by imaging a rotating sample positioned between an X-ray source and…

Fluorescence microscopy is one of the most versatile imaging method in biology. However, the resolution of a conventional wide-field fluorescence microscope is limited by the diffraction of light to several hundred nanometers. Stochastic optical reconstruction microscopy (STORM)…

Images obtained in a TEM or a STEM are never projections of a structure. The fast electron interacts strongly with the nuclear charges and the shell electrons of the sample atoms and strong diffraction effects result from this interaction. As such the image of even a single atom…

Energy dispersive x-ray spectroscopy (EDS) is widely used as a chemical analysis technique in scanning electron microscopy (SEM). It enables the detection of elements both qualitatively and quantitatively simultaneously with any imaging mode of the SEM. In the last decade the…

Cryo lamella-on-grid preparation is a FIB-based approach for the preparation of cellular samples for subsequent study by cryo-electron tomography (ET)  and which is applicable to all kinds of cells grown or deposited directly on EM grids. With the ion beam incident under a…

Immuno-gold labeling is a technique used for the identification, localization, and distribution of proteins, antigens, and other macromolecules of interest, at an ultrastructural level, with high resolution. It is a very powerful technique for identifying active sites and the…

Sequential cyclic removal of nanometric layers from the sample block face and the SEM image acquisition of each newly produced surface. In this manner, hundreds to several thousand of SEM images can be collected in automatic regime, and then processed to generate a 3D dataset of…

Many biological insights can be obtained by combining the power of Fluorescence Microscopy with that of Electron Microscopy to study the same sample – this is called Correlative Light and Electron Microscopy (CLEM).

In Fluorescence Microscopy, specific biological entities can…

Energy dispersive x-ray spectroscopy (EDS) is widely used as a chemical analysis technique in scanning electron microscopy (SEM). It enables the detection of elements both qualitatively and quantitatively simultaneously with any imaging mode of the SEM. In the last decade the…

Cryogenic transmission electron microscopy is conducted on specimens that are cooled in the microscope. Cryogenic  observation, such as at liquid nitrogen temperature, improves the stability of the material or allows for observing a material whose properties change at lower…

Energy Dispersive X-ray spectrometer (EDS) Bruker, crystal 60mm. Elemental EDS analysis of sample surface or milled cross sections.

Cathodoluminescence (CL) - is the emission of light as a result of the interaction of a material with the electron beam. CL spectrometer and detector in SEM can be used to characterize the composition, optical and electronic properties of materials. A CL spectrometer and detector…

Energy Dispersive X-ray spectrometer (EDS) Bruker, crystal 60mm. Elemental EDS analysis of sample surface or milled cross sections at -160C to room temperature.

Single particle cryo-EM is used for determining the 3D structure of biological macromolecules such as proteins and nucleic acid complexes. The technique involves imaging of many (tens or hundreds of thousands) copies of a purified macromolecule under cryo-conditions. Then…

Precise site specific cross sectioning with accuracy <100 nm of a sample for subsequent imaging via integrated high resolution SEM.

Tomography aims at the reconstruction of the three-dimensional structure of a sample from two dimensional representations. The most common form of tomography in materials science is the reconstruction from a set of images of a single object taken under various viewing directions…

Low vacuum (LV) or variable pressure (VP) scanning electron microscopes are a group of special SEMs used mainly for uncoated nonconductive and soft materials. The SEM chamber’s vacuum can be varied by the introduction of gas molecules such as H₂O or N₂ at levels of 20-2000 Pa…

Nano-mechanics is a field devoted to the characterization of nanomaterials or bulk material mechanical properties and behavior at the nanoscale. Measurements of the mechanical properties and the assessment of materials’ deformation mechanisms at the nanoscale have presented new…

Scanning transmission electron microscopy (STEM) is an imaging method that can be used both in TEM and SEM. In SEM extremely low accelerating voltages (2-30kV) can be used to image very thin sections. The technique requires a special detector (diode) that is mounted under the…

Cathodoluminescence (CL) - is the emission of light as a result of the interaction of a material with the electron beam. CL spectrometer and detector in SEM can be used to characterize the composition, optical and electronic properties of materials. A CL spectrometer and detector…

Cryogenic stage for visualization and processing of frozen or sensitive samples allows native preservation of the structure, reduces radiation damage caused by electron / ion beam.

Recent advances in fabrication of MEMS devices have renewed interest to reveal dynamic processes in materials with high spatial and temporal resolution in the TEM. Transformations in liquid and gaseous environment, upon heating or biasing, enable for instance the investigation of…

An environmental scanning electron microscope can work at a higher chamber pressure compared to regular SEM being operated at low pressures (10^-5-10^-7 mbar). Wet mode SEM is a special case where water vapor is introduced into the microscope chamber at a pressure as high as 2000…

Tomography is a method where multiple images of a unique object are taken at a range of angular views. These images are combined and from them a 3D reconstruction is calculated and refined.

TEM and STEM imaging can be used for tomography, each with specific strengths and…

Preparation of a thin (~50-100 nm) site-specific specimen for subsequent TEM / STEM analytical observation (In-situ Lift-Out lamellae preparation).

Temperature control of samples in SEM is used for different applications, among them water condensation and evaporation, particles thermal migration, phase transformation, in situ synthesis, low temperature spectroscopy and more. The sample’s temperature in the SEM can be…

Conventional chemical fixation methods require the removal of water, the main constituent of most biological samples, and often result in various artifacts. Solidification of aqueous samples by lowering their kinetic energy, i.e., freezing, is an alternative physical means for…

Scanning transmission electron microscopy (STEM) is an imaging method that can be used both in TEM and SEM. In SEM extremely low accelerating voltages (2-30kV) can be used to image very thin sections. The technique requires a special detector (diode) that is mounted under the…

An illustration of the high-pressure freezing-freeze substitution method.

figure by Neta Varsano

Vitrification provides the best-known means for the preservation of aqueous samples in their native state, since the only perturbation that occurs during vitrification is…

Nano-mechanics is a field devoted to the characterization of nanomaterials or bulk material mechanical properties and behavior at the nanoscale. Measurements of the mechanical properties and the assessment of materials’ deformation mechanisms at the nanoscale have presented new…

An illustration of the Tokuyasu method.

Figure by Neta Varsano

In the Tokuyasu procedure, the sample is fixed using a moderate fixative, typically 0.1% GA 4% PFS in Cacodylate buffer, after which the cell pellet is embedded in gelatin, cut into small cubes, and…

Many biological insights can be obtained by combining the power of Fluorescence Microscopy with that of Electron Microscopy to study the same sample – this is called Correlative Light and Electron Microscopy (CLEM). In Fluorescence Microscopy, specific biological entities can be…

Characterization and imaging of hydrated samples, and specifically biological samples, under electron microscopes is challenging as these operate under dry high vacuum conditions. Unless an environmental SEM is available, any moist or gas vapor found in the chamber causes severe…

High throughput SEM and large samples (millimeters and more) imaging are quite limited and usually are not applicable for high resolution imaging. Software solutions for automated acquisition can be used to overcome the challenge. The Quattro S ESEM (Thermo Fisher Scientific) is…