扫描电子显微镜扫描电子显微镜
Elizabeth R Fischer1, Bryan T Hansen1, Vinod Nair1
1Electron Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana.
Current protocols
|May 8, 2024
概括
本指南详细介绍了生物样本的扫描电子显微镜 (SEM) 基本技术. 学习最佳的准备和成像方法,以尽量减少文物,并实现高分辨率的地形可视化.
科学领域:
- 显微镜的使用方法
- 材料科学 材料科学 材料科学
- 生物学 生物学 生物学
背景情况:
- 扫描电子显微镜 (SEM) 对于可视化样本地形至关重要.
- 样本准备对于最小化文物和保持结构完整性至关重要.
- 标准的SEM操作要求标本与高真空环境兼容.
研究的目的:
- 为SEM提供日常生物样本准备的基本技术和技巧.
- 引导用户保护不稳定或脆弱的结构.
- 详细说明免疫标记策略和显微镜成像参数,以实现最佳的SEM检查.
主要方法:
- 化学固定和脱水协议,以减少结构工件和收缩.
- 基板选择和涂层方法以减轻充电工件.
- 临界点干燥和样品稳定的替代方法.
- 提高结构可视化的免疫标记策略.
- 机械和冷破碎技术用于暴露内部结构.
- 喷雾涂层用于提高导电性.
主要成果:
- 展示了在SEM样本准备过程中最大限度地减少化学加工工件的方法.
- 概述了脱水技术,以防止收缩,以实现高真空兼容性.
- 介绍了通过基板选择和涂层来减少充电器件的策略.
- 详细说明了保护微妙生物结构的协议.
- 解释免疫标记和断裂技术,以进行详细的结构分析.
结论:
- 掌握SEM样本的准备是精准地形可视化生物样本的关键.
- 仔细选择固定,脱水,安装和成像参数可以最大限度地减少文物.
- 这篇文章是对各种生物标本的常规SEM检查的全面资源.
相关概念视频
Scanning Electron Microscopy
4.2K
A scanning electron microscope (SEM) is used to study the surface features of a sample by using an electron beam that scans the sample surface in a two-dimensional manner. Typically, areas between ~1 centimeter to 5 micrometers in width can be imaged. SEM can be used to image bacteria, viruses, tissues as well as larger samples like insects. Conventional SEM gives a magnification ranging from 20X to 30,000X and spatial resolution of 50 to 100 nanometers.
Fundamental Principles
Accelerated...
Fundamental Principles
Accelerated...
4.2K
Overview of Electron Microscopy
9.0K
The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can only magnify 1000X, and a few can magnify up to 1500X. Electrons, like electromagnetic radiation, can behave like waves, but with wavelengths of 0.005 nm, they produce significantly greater resolution up to 0.05 nm as compared to 500 nm for visible light. An electron microscope (EM) can create a sharp image that is magnified up to 2,000,000X.
9.0K
Overview of Microscopy Techniques
10.2K
The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes that leveraged nonvisible light, such as fluorescence microscopy that uses an ultraviolet light source and electron microscopy that uses short-wavelength electron beams. These advances significantly improved magnification, image resolution, and contrast. By comparison, the...
10.2K
Electron Microscope Tomography and Single-particle Reconstruction
2.4K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.4K
Transmission Electron Microscopy
5.5K
In 1931, physicist Ernst Ruska—building on the idea that magnetic fields can direct an electron beam just as lenses can direct a beam of light in an optical microscope—developed the first prototype of the electron microscope. This development led to the development of the field of electron microscopy. In the transmission electron microscope (TEM), electrons are produced by a hot tungsten element and accelerated by a potential difference in an electron gun, which gives them up to 400...
5.5K
Preparation of Samples for Electron Microscopy
5.4K
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...
5.4K


