Electron Sample Interaction
Electron Sample Interaction - Related Videos
01:20
Preparation of Samples for Electron Microscopy
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2023
To be visualized by an electron microscope, either transmission or scanning, biological samples need to be fixed (stabilized) so the electron beam does not destroy them and dried thoroughly (desiccated/dehydrated) so the vacuum does not affect them. Fixation needs to be done as quickly as possible because the sample properties will start changing as soon as it is removed from its natural environment. For example, in a tissue sample, the oxygen levels begin decreasing, causing an altered...
10:49
Method to Visualize and Analyze Membrane Interacting Proteins by Transmission Electron Microscopy
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Cited by 11 •
2017
Many proteins perform their function when attached to membrane surfaces. The binding of extrinsic proteins on nanodisc membranes can be indirectly imaged by transmission electron microscopy. We show that the characteristic stacking (rouleau) of nanodiscs induced by the negative stain sodium phosphotungstate is prevented by the binding of extrinsic protein.
08:04
Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography
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Cited by 9 •
2017
This report describes a sample preparation protocol and specific imaging conditions for performing scanning transmission electron tomography of thick biological specimens.
06:10
Preparation of Sample Support Films in Transmission Electron Microscopy using a Support Floatation Block
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Cited by 10 •
2021
Sample preparation for cryo-electron microscopy (cryo-EM) is a significant bottleneck in the structure determination workflow of this method. Here, we provide detailed methods for using an easy-to-use, three-dimensionally printed block for the preparation of support films to stabilize samples for transmission EM studies.
10:52
Correlative Light and Electron Microscopy to Study Microglial Interactions with β-Amyloid Plaques
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Cited by 30 •
2016
This article describes a protocol for visualizing amyloid Aβ plaques in Alzheimer's disease mouse models using methoxy-X04, which crosses the blood-brain barrier and selectively binds to β-pleated sheets found in dense core Aβ plaques. It allows pre-screening of plaque-containing tissue sections prior to immunostaining and processing for electron microscopy.
FAQs
Elastic scattering primarily changes an electron’s direction, while inelastic scattering transfers energy to the specimen. These different interactions influence how many electrons emerge from, pass through, or lose energy within the sample. Their relative contributions help determine image contrast and the strength of measurable signals, so interpreting contrast requires considering both scattering pathways.
The interaction can produce secondary electrons, backscattered electrons, characteristic X-rays, and other measurable signals. Secondary and backscattered electrons support imaging of specimen surfaces or structural variation, while characteristic X-rays provide information about elemental composition. In biological samples, these signals can complement structural observations with chemical or labeling-related information.
Beam energy, specimen thickness, and preparation conditions are central variables. Changing beam energy alters how electrons interact with the material, while thickness affects how far electrons travel and which signals can emerge. Preparation conditions also influence the resulting contrast. Adjusting these factors helps balance image quality, analytical information, and radiation damage.
In scanning electron microscopy, interaction-generated signals are used to examine specimen surfaces, whereas transmission electron microscopy relies on electrons passing through the specimen to reveal internal ultrastructure. Both methods depend on electron scattering and signal production, but specimen thickness and preparation become especially important for transmission-based observations of cellular interiors.
Optimization begins by matching beam energy and specimen thickness to the intended observation, then considering preparation conditions that support useful contrast. Researchers must also monitor the trade-off between stronger or clearer signals and beam-induced radiation damage. This controlled adjustment helps preserve biological structure while obtaining interpretable surface, internal, compositional, or labeling information.
Electron sample interaction underpins high-resolution biological imaging and analysis. It enables examination of cell surfaces with scanning methods and internal ultrastructure with transmission methods. Interaction-generated signals can also support elemental composition measurements and the visualization of molecularly labeled regions. Together, these capabilities connect electron microscopy with structural, chemical, and label-based biological investigations.