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An electron microscope is a microscope that uses a beam of electrons as a source of illumination. They use electron optics that are analogous to the glass lenses of an optical light microscope to control the electron beam, for instance focusing them to produce magnified images or electron diffraction patterns. As the wavelength of an electron can be up to 100,000 times smaller than that of visible light, electron microscopes have a much higher resolution of about 0.1 nm, which compares to about 200 nm for light microscopes. Electron microscope may refer to:

• Transmission electron microscopy (TEM) where swift electrons go through a thin sample
• Scanning transmission electron microscopy (STEM) which is similar to TEM with a scanned electron probe
• Scanning electron microscope (SEM) which is similar to STEM, but with thick samples
• Electron microprobe similar to a SEM, but more for chemical analysis
• Low-energy electron microscopy (LEEM), used to image surfaces
• Photoemission electron microscopy (PEEM) which is similar to LEEM using electrons emitted from surfaces by photons

Additional details can be found in the above links. This article contains some general information mainly about transmission electron microscopes.

History

Many developments laid the groundwork of the electron optics used in microscopes. One significant step was the work of Hertz in 1883 who made a cathode-ray tube with electrostatic and magnetic deflection, demonstrating manipulation of the direction of an electron beam. Others were focusing of the electrons by an axial magnetic field by Emil Wiechert in 1899, improved oxide-coated cathodes which produced more electrons by Arthur Wehnelt in 1905 and the development of the electromagnetic lens in 1926 by Hans Busch. According to Dennis Gabor, the physicist Leó Szilárd tried in 1928 to convince him to build an electron microscope, for which Szilárd had filed a patent.

To this day the issue of who invented the transmission electron microscope is controversial. In 1928, at the Technische Hochschule in Charlottenburg (now Technische Universität Berlin), Adolf Matthias (Professor of High Voltage Technology and Electrical Installations) appointed Max Knoll to lead a team of researchers to advance research on electron beams and cathode-ray oscilloscopes. The team consisted of several PhD students including Ernst Ruska. In 1931, Max Knoll and Ernst Ruska successfully generated magnified images of mesh grids placed over an anode aperture. The device, a replicate of which is shown in the figure, used two magnetic lenses to achieve higher magnifications, the first electron microscope. (Max Knoll died in 1969, so did not receive a share of the 1986 Nobel prize for the invention of electron microscopes.)

Apparently independent of this effort was work at Siemens-Schuckert by Reinhold Rüdenberg. According to patent law (U.S. Patent No. 2058914 and 2070318, both filed in 1932), he is the inventor of the electron microscope, but it is not clear when he had a working instrument. He stated in a very brief article in 1932 that Siemens had been working on this for some years before the patents were filed in 1932, claiming that his effort was parallel to the university development. He died in 1961, so similar to Max Knoll, was not eligible for a share of the 1986 Nobel prize.

In the following year, 1933, Ruska and Knoll built the first electron microscope that exceeded the resolution of an optical (light) microscope. Four years later, in 1937, Siemens financed the work of Ernst Ruska and Bodo von Borries, and employed Helmut Ruska, Ernst's brother, to develop applications for the microscope, especially with biological specimens. Also in 1937, Manfred von Ardenne pioneered the scanning electron microscope. Siemens produced the first commercial electron microscope in 1938. The first North American electron microscopes were constructed in the 1930s, at the Washington State University by Anderson and Fitzsimmons and at the University of Toronto by Eli Franklin Burton and students Cecil Hall, James Hillier, and Albert Prebus. Siemens produced a transmission electron microscope (TEM) in 1939. Although current transmission electron microscopes are capable of two million times magnification, as scientific instruments they remain similar but with improved optics.

In the 1940s, high-resolution electron microscopes were developed, enabling greater magnification and resolution. By 1965, Albert Crewe at the University of Chicago introduced the scanning transmission electron microscope using a field emission source, enabling scanning microscopes at high resolution. By the early 1980s improvements in mechanical stability as well as the use of higher accelerating voltages enabled imaging of materials at the atomic scale. In the 1980s, the field emission gun became common for electron microscopes, improving the image quality due to the additional coherence and lower chromatic aberrations. The 2000s were marked by advancements in aberration-corrected electron microscopy, allowing for significant improvements in resolution and clarity of images.

Types

Transmission electron microscope (TEM)

The original form of the electron microscope, the transmission electron microscope (TEM), uses a high voltage electron beam to illuminate the specimen and create an image. An electron beam is produced by an electron gun, with the electrons typically having energies in the range 20 to 400 keV, focused by electromagnetic lenses, and transmitted through the specimen. When it emerges from the specimen, the electron beam carries information about the structure of the specimen that is magnified by lenses of the microscope. The spatial variation in this information (the "image") may be viewed by projecting the magnified electron image onto a detector. For example, the image may be viewed directly by an operator using a fluorescent viewing screen coated with a phosphor or scintillator material such as zinc sulfide. A high-resolution phosphor may also be coupled by means of a lens optical system or a fibre optic light-guide to the sensor of a digital camera. Direct electron detectors have no scintillator and are directly exposed to the electron beam, which addresses some of the limitations of scintillator-coupled cameras.

The resolution of TEMs is limited primarily by spherical aberration, but a new generation of hardware correctors can reduce spherical aberration to increase the resolution in high-resolution transmission electron microscopy (HRTEM) to below 0.5 angstrom (50 picometres), enabling magnifications above 50 million times. The ability of HRTEM to determine the positions of atoms within materials is useful for nano-technologies research and development.

Scanning transmission electron microscope (STEM)

The STEM rasters a focused incident probe across a specimen. The high resolution of the TEM is thus possible in STEM. The focusing action (and aberrations) occur before the electrons hit the specimen in the STEM, but afterward in the TEM. The STEMs use of SEM-like beam rastering simplifies annular dark-field imaging, and other analytical techniques, but also means that image data is acquired in serial rather than in parallel fashion.

Scanning electron microscope (SEM)

The SEM produces images by probing the specimen with a focused electron beam that is scanned across the specimen (raster scanning). When the electron beam interacts with the specimen, it loses energy by a variety of mechanisms. These interactions lead to, among other events, emission of low-energy secondary electrons and high-energy backscattered electrons, light emission (cathodoluminescence) or X-ray emission, all of which provide signals carrying information about the properties of the specimen surface, such as its topography and composition. The image displayed by SEM represents the varying intensity of any of these signals into the image in a position corresponding to the position of the beam on the specimen when the signal was generated.

SEMs are different from TEMs in that they use electrons with much lower energy, generally below 20 keV, while TEMs generally use electrons with energies in the range of 80-300 keV. Thus, the electron sources and optics of the two microscopes have different designs, and they are normally separate instruments.

Main operating modes

Diffraction contrast imaging

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Phase contrast imaging

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High resolution imaging

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Chemical analysis

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Electron diffraction

Transmission electron microscopes can be used in electron diffraction mode where a map of the angles of the electrons leaving the sample is produced. The advantages of electron diffraction over X-ray crystallography are primarily in the size of the crystals. In X-ray crystallography, crystals are commonly visible by the naked eye and are generally in the hundreds of micrometers in length. In comparison, crystals for electron diffraction must be less than a few hundred nanometers in thickness, and have no lower boundary of size. Additionally, electron diffraction is done on a TEM, which can also be used to obtain many other types of information, rather than requiring a separate instrument.

Sample preparation

Samples for electron microscopes mostly cannot be observed directly. The samples need to be prepared to stabilize the sample and enhance contrast. Preparation techniques differ vastly in respect to the sample and its specific qualities to be observed as well as the specific microscope used.

Scanning Electron Microscope (SEM)

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To prevent charging and enhance the signal in SEM, non-conductive samples (e.g. biological samples as in figure) can be sputter-coated in a thin film of metal.

Transmission electron microscope

Materials to be viewed in a transmission electron microscope (TEM) may require processing to produce a suitable sample. The technique required varies depending on the specimen and the analysis required:

• Chemical fixation – for biological specimens this aims to stabilize the specimen's mobile macromolecular structure by chemical crosslinking of proteins with aldehydes such as formaldehyde and glutaraldehyde, and lipids with osmium tetroxide.

• Cryofixation – freezing a specimen so that the water forms vitreous (non-crystalline) ice. This preserves the specimen in a snapshot of its native state. Methods to achieve this vitrification include plunge freezing rapidly in liquid ethane, and high pressure freezing. An entire field called cryo-electron microscopy has branched from this technique. With the development of cryo-electron microscopy of vitreous sections (CEMOVIS) and cryo-focused ion beam milling of lamellae, it is now possible to observe samples from virtually any biological specimen close to its native state.
• Dehydration – replacement of water with organic solvents such as ethanol or acetone, followed by critical point drying or infiltration with embedding resins. See also freeze drying.
• Embedding, biological specimens – after dehydration, tissue for observation in the transmission electron microscope is embedded so it can be sectioned ready for viewing. To do this the tissue is passed through a 'transition solvent' such as propylene oxide (epoxypropane) or acetone and then infiltrated with an epoxy resin such as Araldite, Epon, or Durcupan; tissues may also be embedded directly in water-miscible acrylic resin. After the resin has been polymerized (hardened) the sample is sectioned by ultramicrotomy and stained.
• Embedding, materials – after embedding in resin, the specimen is usually ground and polished to a mirror-like finish using ultra-fine abrasives.
• Freeze-fracture or freeze-etch – a preparation method particularly useful for examining lipid membranes and their incorporated proteins in "face on" view.

  

  

  The fresh tissue or cell suspension is frozen rapidly (cryofixation), then fractured by breaking (or by using a microtome) while maintained at liquid nitrogen temperature. The cold fractured surface (sometimes "etched" by increasing the temperature to about −100 °C for several minutes to let some ice sublime) is then shadowed with evaporated platinum or gold at an average angle of 45° in a high vacuum evaporator. The second coat of carbon, evaporated perpendicular to the average surface plane is often performed to improve the stability of the replica coating. The specimen is returned to room temperature and pressure, then the extremely fragile "pre-shadowed" metal replica of the fracture surface is released from the underlying biological material by careful chemical digestion with acids, hypochlorite solution or SDS detergent. The still-floating replica is thoroughly washed free from residual chemicals, carefully fished up on fine grids, dried then viewed in the TEM.
• Freeze-fracture replica immunogold labeling (FRIL) – the freeze-fracture method has been modified to allow the identification of the components of the fracture face by immunogold labeling. Instead of removing all the underlying tissue of the thawed replica as the final step before viewing in the microscope the tissue thickness is minimized during or after the fracture process. The thin layer of tissue remains bound to the metal replica so it can be immunogold labeled with antibodies to the structures of choice. The thin layer of the original specimen on the replica with gold attached allows the identification of structures in the fracture plane. There are also related methods which label the surface of etched cells and other replica labeling variations.
• Ion beam milling – thins samples until they are transparent to electrons by firing ions (typically argon) at the surface from an angle and sputtering material from the surface. A subclass of this is focused ion beam milling, where gallium ions are used to produce an electron transparent membrane or 'lamella' in a specific region of the sample, for example through a device within a microprocessor or a focused ion beam SEM. Ion beam milling may also be used for cross-section polishing prior to analysis of materials that are difficult to prepare using mechanical polishing.
• Negative stain – suspensions containing nanoparticles or fine biological material (such as viruses and bacteria) are briefly mixed with a dilute solution of an electron-opaque solution such as ammonium molybdate, uranyl acetate (or formate), or phosphotungstic acid. This mixture is applied to an EM grid, pre-coated with a plastic film such as formvar, blotted, then allowed to dry. Viewing of this preparation in the TEM should be carried out without delay for best results. The method is important in microbiology for fast but crude morphological identification, but can also be used as the basis for high-resolution 3D reconstruction using EM tomography methodology when carbon films are used for support.
• Sectioning – produces thin slices of the specimen, semitransparent to electrons. These can be cut using ultramicrotomy on an ultramicrotome with a glass or diamond knife to produce ultra-thin sections about 60–90 nm thick. Disposable glass knives are also used because they can be made in the lab and are much cheaper. Sections can also be created in situ by milling in a focused ion beam SEM, where the section is known as a lamella.
• Staining – uses heavy metals such as lead, uranium or tungsten to scatter imaging electrons and thus give contrast between different structures, since many (especially biological) materials are nearly "transparent" to electrons (weak phase objects). In biology, specimens can be stained "en bloc" before embedding and also later after sectioning. Typically thin sections are stained for several minutes with an aqueous or alcoholic solution of uranyl acetate followed by aqueous lead citrate.

EM workflows

In their most common configurations, electron microscopes produce images with a single brightness value per pixel, with the results usually rendered in greyscale. However, often these images are then colourized through the use of feature-detection software, or simply by hand-editing using a graphics editor. This may be done to clarify structure or for aesthetic effect and generally does not add new information about the specimen.

Electron microscopes are now frequently used in more complex workflows, with each workflow typically using multiple technologies to enable more complex and/or more quantitative analyses of a sample. A few examples are outlined below, but this should not be considered an exhaustive list. The choice of workflow will be highly dependent on the application and the requirements of the corresponding scientific questions, such as resolution, volume, nature of the target molecule, etc.

For example, images from light and electron microscopy of the same region of a sample can be overlaid to correlate the data from the two modalities. This is commonly used to provide higher resolution contextual EM information about a fluorescently labelled structure. This correlative light and electron microscopy (CLEM) is one of a range of correlative workflows now available. Another example is high resolution mass spectrometry (ion microscopy), which has been used to provide correlative information about subcellular antibiotic localisation, data that would be difficult to obtain by other means.

The initial role of electron microscopes in imaging two-dimensional slices (TEM) or a specimen surface (SEM with secondary electrons) has also increasingly expanded into the depth of samples. An early example of these ‘volume EM’ workflows was simply to stack TEM images of serial sections cut through a sample. The next development was virtual reconstruction of a thick section (200-500 nm) volume by backprojection of a set of images taken at different tilt angles - TEM tomography.

Serial imaging for volume EM

To acquire volume EM datasets of larger depths than TEM tomography (micrometers or millimeters in the z axis), a series of images taken through the sample depth can be used. For example, ribbons of serial sections can be imaged in a TEM as described above, and when thicker sections are used, serial TEM tomography can be used to increase the z-resolution. More recently, back scattered electron (BSE) images can be acquired of a larger series of sections collected on silicon wafers, known as SEM array tomography. An alternative approach is to use BSE SEM to image the block surface instead of the section, after each section has been removed. By this method, an ultramicrotome installed in an SEM chamber can increase automation of the workflow; the specimen block is loaded in the chamber and the system programmed to continuously cut and image through the sample. This is known as serial block face SEM. A related method uses focused ion beam milling instead of an ultramicrotome to remove sections. In these serial imaging methods, the output is essentially a sequence of images through a specimen block that can be digitally aligned in sequence and thus reconstructed into a volume EM dataset. The increased volume available in these methods has expanded the capability of electron microscopy to address new questions, such as mapping neural connectivity in the brain, and membrane contact sites between organelles.

Disadvantages

Electron microscopes are expensive to build and maintain. Microscopes designed to achieve high resolutions must be housed in stable buildings (sometimes underground) with special services such as magnetic field canceling systems.

The samples largely have to be viewed in vacuum, as the molecules that make up air would scatter the electrons. An exception is liquid-phase electron microscopy using either a closed liquid cell or an environmental chamber, for example, in the environmental scanning electron microscope, which allows hydrated samples to be viewed in a low-pressure (up to 20 Torr or 2.7 kPa) wet environment. Various techniques for in situ electron microscopy of gaseous samples have been developed.

Scanning electron microscopes operating in conventional high-vacuum mode usually image conductive specimens; therefore non-conductive materials require conductive coating (gold/palladium alloy, carbon, osmium, etc.). The low-voltage mode of modern microscopes makes possible the observation of non-conductive specimens without coating. Non-conductive materials can be imaged also by a variable pressure (or environmental) scanning electron microscope.

Small, stable specimens such as carbon nanotubes, diatom frustules and small mineral crystals (asbestos fibres, for example) require no special treatment before being examined in the electron microscope. Samples of hydrated materials, including almost all biological specimens, have to be prepared in various ways to stabilize them, reduce their thickness (ultrathin sectioning) and increase their electron optical contrast (staining). These processes may result in artifacts, but these can usually be identified by comparing the results obtained by using radically different specimen preparation methods. Since the 1980s, analysis of cryofixed, vitrified specimens has also become increasingly used by scientists, further confirming the validity of this technique.

See also

• List of materials analysis methods
• Electron diffraction
• Electron energy loss spectroscopy (EELS)
• Electron microscope images
• Energy filtered transmission electron microscopy (EFTEM)
• Environmental scanning electron microscope (ESEM)
• Immune electron microscopy
• In situ electron microscopy
• Low-energy electron microscopy
• Microscope image processing
• Microscopy
• Nanotechnology
• Scanning confocal electron microscopy
• Scanning electron microscope (SEM)
• Thin section
• Transmission Electron Aberration-Corrected Microscope

References

1. "Electron microscope". Encyclopaedia Britannica. Retrieved June 26, 2024.
2. Calbick CJ (1944). "Historical Background of Electron Optics". Journal of Applied Physics. 15 (10): 685–690. Bibcode:1944JAP....15..685C. doi:10.1063/1.1707371.
3. Hertz H (2019). "Introduction to Heinrich Hertz's Miscellaneous Papers (1895) by Philipp Lenard". In Mulligan JF (ed.). Heinrich Rudolf Hertz (1857-1894) : a collection of articles and addresses. Routledge. pp. 87–88. doi:10.4324/9780429198960-4. ISBN 978-0-429-19896-0.
4. Wiechert E (1899). "Experimentelle Untersuchungen über die Geschwindigkeit und die magnetische Ablenkbarkeit der Kathodenstrahlen" [Experimental Investigations on the Velocity and Magnetic Deflection of Cathode Rays]. Annalen der Physik und Chemie (in German). 305 (12): 739–766. Bibcode:1899AnP...305..739W. doi:10.1002/andp.18993051203.
5. Wehnelt A (1905). "X. On the discharge of negative ions by glowing metallic oxides, and allied phenomena". The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. 10 (55): 80–90. doi:10.1080/14786440509463347.
6. Busch H (1926). "Berechnung der Bahn von Kathodenstrahlen im axialsymmetrischen elektromagnetischen Felde" [Calculation of the trajectory of cathode rays in an axially symmetric electromagnetic field]. Annalen der Physik (in German). 386 (25): 974–993. Bibcode:1926AnP...386..974B. doi:10.1002/andp.19263862507.
7. Dannen, Gene (1998) Leo Szilard the Inventor: A Slideshow (1998, Budapest, conference talk). dannen.com
8. Mulvey T (1962). "Origins and historical development of the electron microscope". British Journal of Applied Physics. 13 (5): 197–207. doi:10.1088/0508-3443/13/5/303.
9. Tao Y (2018). "A Historical Investigation of the Debates on the Invention and Invention Rights of Electron Microscope". Proceedings of the 3rd International Conference on Contemporary Education, Social Sciences and Humanities (ICCESSH 2018). Advances in Social Science, Education and Humanities Research. Atlantis Press. pp. 1438–1441. doi:10.2991/iccessh-18.2018.313. ISBN 978-94-6252-528-3.
10. Freundlich MM (October 1963). "Origin of the Electron Microscope". Science. 142 (3589): 185–188. Bibcode:1963Sci...142..185F. doi:10.1126/science.142.3589.185. PMID 14057363.
11. Rüdenberg R (2010). Origin and Background of the Invention of the Electron Microscope. Advances in Imaging and Electron Physics. Vol. 160. pp. 171–205. doi:10.1016/s1076-5670(10)60005-5. ISBN 978-0-12-381017-5..
12. Knoll M, Ruska E (1932). "Beitrag zur geometrischen Elektronenoptik. I". Annalen der Physik. 404 (5): 607–640. Bibcode:1932AnP...404..607K. doi:10.1002/andp.19324040506.
13. Knoll M, Ruska E (1932). "Das Elektronenmikroskop". Zeitschrift für Physik (in German). 78 (5–6): 318–339. Bibcode:1932ZPhy...78..318K. doi:10.1007/BF01342199.
14. Rüdenberg R. "Apparatus for producing images of objects". Patent Public Search Basic. Retrieved 24 February 2023.
15. Rüdenberg R. "Apparatus for producing images of objects". Patent Public Search Basic. Retrieved 24 February 2023.
16. Rüdenberg R (July 1932). "Elektronenmikroskop". Die Naturwissenschaften. 20 (28): 522. Bibcode:1932NW.....20..522R. doi:10.1007/BF01505383.
17. "History of Electron Microscope". LEO Electron Microscopy. Retrieved June 26, 2024.
18. ^ Ruska, Ernst (1986). "Ernst Ruska Autobiography". Nobel Foundation. Retrieved 2010-01-31.
19. Kruger DH, Schneck P, Gelderblom HR (May 2000). "Helmut Ruska and the visualisation of viruses". Lancet. 355 (9216): 1713–1717. doi:10.1016/S0140-6736(00)02250-9. PMID 10905259.
20. Von Ardenne M, Beischer D (1940). "Untersuchung von Metalloxyd-Rauchen mit dem Universal-Elektronenmikroskop" [Investigation of metal oxide smoking with the universal electron microscope]. Zeitschrift für Elektrochemie und Angewandte Physikalische Chemie (in German). 46 (4): 270–277. doi:10.1002/bbpc.19400460406.
21. History of electron microscopy, 1931–2000. Authors.library.caltech.edu (2002-12-10). Retrieved on 2017-04-29.
22. "North America's first electron microscope".
23. "James Hillier". Inventor of the Week: Archive. 2003-05-01. Archived from the original on 2003-08-23. Retrieved 2010-01-31.
24. Hawkes PW (2021). The Beginnings of Electron Microscopy. Part 1. London San Diego, CA Cambridge, MA Oxford: Academic Press. ISBN 978-0-323-91507-6.
25. Crewe AV, Eggenberger DN, Wall J, Welter LM (1968-04-01). "Electron Gun Using a Field Emission Source". Review of Scientific Instruments. 39 (4): 576–583. Bibcode:1968RScI...39..576C. doi:10.1063/1.1683435.
26. Crewe AV (November 1966). "Scanning electron microscopes: is high resolution possible?". Science. 154 (3750): 729–738. Bibcode:1966Sci...154..729C. doi:10.1126/science.154.3750.729. PMID 17745977.
27. Smith DJ, Camps RA, Freeman LA, Hill R, Nixon WC, Smith KC (May 1983). "Recent improvements to the Cambridge University 600 kV High Resolution Electron Microscope". Journal of Microscopy. 130 (2): 127–136. doi:10.1111/j.1365-2818.1983.tb04211.x.
28. Spence JC (2013). High-Resolution Electron Microscopy. doi:10.1093/acprof:oso/9780199668632.001.0001. ISBN 978-0-19-966863-2.
29. Hawkes PW (28 September 2009). "Aberration correction past and present". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 367 (1903): 3637–3664. Bibcode:2009RSPTA.367.3637H. doi:10.1098/rsta.2009.0004. PMID 19687058.
30. Rose HH (June 2009). "Historical aspects of aberration correction". Journal of Electron Microscopy. 58 (3): 77–85. doi:10.1093/jmicro/dfp012. PMID 19254915.
31. Cheng Y, Grigorieff N, Penczek PA, Walz T (April 2015). "A primer to single-particle cryo-electron microscopy". Cell. 161 (3): 438–449. doi:10.1016/j.cell.2015.03.050. PMC 4409659. PMID 25910204.
32. Erni R, Rossell MD, Kisielowski C, Dahmen U (March 2009). "Atomic-resolution imaging with a sub-50-pm electron probe". Physical Review Letters. 102 (9): 096101. Bibcode:2009PhRvL.102i6101E. doi:10.1103/PhysRevLett.102.096101. PMID 19392535.
33. "The Scale of Things". Office of Basic Energy Sciences, U.S. Department of Energy. 2006-05-26. Archived from the original on 2010-02-01. Retrieved 2010-01-31.
34. O'Keefe MA, Allard LF (2004-01-18). "Sub-Ångstrom Electron Microscopy for Sub-Ångstrom Nano-Metrology" (PDF). Information Bridge: DOE Scientific and Technical Information – Sponsored by OSTI.
35. "Elements of a Transmission Electron Microscope". Transmission Electron Microscopy. Springer Series in Optical Sciences. Vol. 36. 2008. pp. 75–138. doi:10.1007/978-0-387-40093-8_4. ISBN 978-0-387-40093-8.
36. "Introduction". Transmission Electron Microscopy. Springer Series in Optical Sciences. Vol. 36. 2008. pp. 1–15. doi:10.1007/978-0-387-40093-8_1. ISBN 978-0-387-40093-8.
37. Dusevich V, Purk J, Eick J (January 2010). "Choosing the Right Accelerating Voltage for SEM (An Introduction for Beginners)". Microscopy Today. 18 (1): 48–52. doi:10.1017/s1551929510991190.
38. ^ Saha A, Nia SS, Rodríguez JA (September 2022). "Electron Diffraction of 3D Molecular Crystals". Chemical Reviews. 122 (17): 13883–13914. doi:10.1021/acs.chemrev.1c00879. PMC 9479085. PMID 35970513.
39. "Electron Microscopy | Thermo Fisher Scientific - US". 2022-04-07. Archived from the original on 2022-04-07. Retrieved 2024-07-13.
40. Cowley JM (1995). Diffraction physics. North Holland personal library (3rd ed.). Amsterdam: Elsevier. ISBN 978-0-444-82218-5.
41. Humbel BM, Schwarz H, Tranfield EM, Fleck RA (2019). "Chemical Fixation". Biological Field Emission Scanning Electron Microscopy. pp. 191–221. doi:10.1002/9781118663233.ch10. ISBN 978-1-118-65406-4.
42. Al-Amoudi A, Norlen LP, Dubochet J (October 2004). "Cryo-electron microscopy of vitreous sections of native biological cells and tissues". Journal of Structural Biology. 148 (1): 131–135. doi:10.1016/j.jsb.2004.03.010. PMID 15363793.
43. ^ Wagner FR, Watanabe R, Schampers R, Singh D, Persoon H, Schaffer M, et al. (June 2020). "Preparing samples from whole cells using focused-ion-beam milling for cryo-electron tomography". Nature Protocols. 15 (6): 2041–2070. doi:10.1038/s41596-020-0320-x. PMC 8053421. PMID 32405053.
44. Luft JH (1 February 1961). "Improvements in epoxy resin embedding methods". The Journal of Cell Biology. 9 (2): 409–414. doi:10.1083/jcb.9.2.409. PMC 2224998. PMID 13764136.
45. Meryman HT, Kafig E (16 August 1955). The Study of Frozen Specimens, Ice Crystals and Ice Crystal Growth by Electron Microscopy (Report). Naval Medical Research Institute. pp. 529–544. NM 000 018.01.09.
46. Steere RL (January 1957). "Electron microscopy of structural detail in frozen biological specimens". The Journal of Biophysical and Biochemical Cytology. 3 (1): 45–60. doi:10.1083/jcb.3.1.45. PMC 2224015. PMID 13416310.
47. Isailović TM, Todosijević MN, Đorđević SM, Savić SD (2017). "Natural Surfactants-Based Micro/Nanoemulsion Systems for NSAIDs—Practical Formulation Approach, Physicochemical and Biopharmaceutical Characteristics/Performances". Microsized and Nanosized Carriers for Nonsteroidal Anti-Inflammatory Drugs. pp. 179–217. doi:10.1016/b978-0-12-804017-1.00007-8. ISBN 978-0-12-804017-1.
48. Moor H, Mühlethaler K (June 1963). "Fine Structure in Frozen-Etched Yeast Cells". The Journal of Cell Biology. 17 (3): 609–628. doi:10.1083/jcb.17.3.609. PMC 2106217. PMID 19866628.
49. Black JA (January 1990). "g - Use of Freeze-Fracture in Neurobiology". In Conn PM (ed.). Methods in Neurosciences. Quantitative and Qualitative Microscopy. Vol. 3. Academic Press. pp. 343–360. doi:10.1016/b978-0-12-185255-9.50025-0. ISBN 9780121852559.
50. ^ Stillwell W (2016). "Long-Range Membrane Properties". An Introduction to Biological Membranes. pp. 221–245. doi:10.1016/b978-0-444-63772-7.00011-7. ISBN 978-0-444-63772-7.
51. Bullivant S, Ames A (June 1966). "A simple freeze-fracture replication method for electron microscopy". The Journal of Cell Biology. 29 (3): 435–447. doi:10.1083/jcb.29.3.435. PMC 2106967. PMID 5962938.
52. Gruijters WT, Kistler J, Bullivant S, Goodenough DA (March 1987). "Immunolocalization of MP70 in lens fiber 16-17-nm intercellular junctions". The Journal of Cell Biology. 104 (3): 565–572. doi:10.1083/jcb.104.3.565. PMC 2114558. PMID 3818793.
53. Pinto da Silva P, Branton D (June 1970). "Membrane splitting in freeze-ethching. Covalently bound ferritin as a membrane marker". The Journal of Cell Biology. 45 (3): 598–605. doi:10.1083/jcb.45.3.598. PMC 2107921. PMID 4918216.
54. Rash JE, Johnson TJ, Hudson CS, Giddings FD, Graham WF, Eldefrawi ME (November 1982). "Labelled-replica techniques: post-shadow labelling of intramembrane particles in freeze-fracture replicas". Journal of Microscopy. 128 (Pt 2): 121–138. doi:10.1111/j.1365-2818.1982.tb00444.x. PMID 6184475.
55. Reynolds ES (April 1963). "The use of lead citrate at high pH as an electron-opaque stain in electron microscopy". The Journal of Cell Biology. 17 (1): 208–212. doi:10.1083/jcb.17.1.208. PMC 2106263. PMID 13986422.
56. Burgess J (1987). Under the Microscope: A Hidden World Revealed. CUP Archive. p. 11. ISBN 978-0-521-39940-1.
57. "Introduction to Electron Microscopy" (PDF). FEI Company. p. 15. Retrieved 12 December 2012.
58. Müller-Reichert T, Verkade P (2017). "Preface". Correlative Light and Electron Microscopy III. Methods in Cell Biology. Vol. 140. pp. xvii. doi:10.1016/S0091-679X(17)30069-9. ISBN 978-0-12-809975-9.
59. Finin P, Khan RM, Oh S, Boshoff HI, Barry CE (May 2023). "Chemical approaches to unraveling the biology of mycobacteria". Cell Chemical Biology. 30 (5): 420–435. doi:10.1016/j.chembiol.2023.04.014. PMC 10201459. PMID 37207631.
60. ^ Peddie CJ, Genoud C, Kreshuk A, Meechan K, Micheva KD, Narayan K, et al. (July 2022). "Volume electron microscopy". Nature Reviews. Methods Primers. 2: 51. doi:10.1038/s43586-022-00131-9. PMC 7614724. PMID 37409324.
61. Crowther RA, Amos LA, Finch JT, De Rosier DJ, Klug A (May 1970). "Three dimensional reconstructions of spherical viruses by fourier synthesis from electron micrographs". Nature. 226 (5244): 421–425. Bibcode:1970Natur.226..421C. doi:10.1038/226421a0. PMID 4314822.
62. White IJ, Burden JJ (2023). "A practical guide to starting SEM array tomography—An accessible volume EM technique". Volume Electron Microscopy. Methods in Cell Biology. Vol. 177. pp. 171–196. doi:10.1016/bs.mcb.2022.12.023. ISBN 978-0-323-91607-3. PMID 37451766.
63. Kolotuev I (July 2024). "Work smart, not hard: How array tomography can help increase the ultrastructure data output". Journal of Microscopy. 295 (1): 42–60. doi:10.1111/jmi.13217. PMID 37626455.
64. Denk W, Horstmann H (November 2004). "Serial block-face scanning electron microscopy to reconstruct three-dimensional tissue nanostructure". PLOS Biology. 2 (11): e329. doi:10.1371/journal.pbio.0020329. PMC 524270. PMID 15514700.
65. Abbott LF, Bock DD, Callaway EM, Denk W, Dulac C, Fairhall AL, et al. (September 2020). "The Mind of a Mouse". Cell. 182 (6): 1372–1376. doi:10.1016/j.cell.2020.08.010. PMID 32946777.
66. Prinz WA, Toulmay A, Balla T (January 2020). "The functional universe of membrane contact sites". Nature Reviews. Molecular Cell Biology. 21 (1): 7–24. doi:10.1038/s41580-019-0180-9. PMC 10619483. PMID 31732717.
67. Song YL, Lin HY, Manikandan S, Chang LM (March 2022). "A Magnetic Field Canceling System Design for Diminishing Electromagnetic Interference to Avoid Environmental Hazard". International Journal of Environmental Research and Public Health. 19 (6): 3664. doi:10.3390/ijerph19063664. PMC 8954143. PMID 35329350.
68. Williamson MJ, Tromp RM, Vereecken PM, Hull R, Ross FM (August 2003). "Dynamic microscopy of nanoscale cluster growth at the solid-liquid interface". Nature Materials. 2 (8): 532–536. Bibcode:2003NatMa...2..532W. doi:10.1038/nmat944. PMID 12872162.
69. Gai PL, Boyes ED (March 2009). "Advances in atomic resolution in situ environmental transmission electron microscopy and 1A aberration corrected in situ electron microscopy". Microscopy Research and Technique. 72 (3): 153–164. arXiv:1705.05754. doi:10.1002/jemt.20668. PMID 19140163.
70. Adrian M, Dubochet J, Lepault J, McDowall AW (1984). "Cryo-electron microscopy of viruses". Nature (Submitted manuscript). 308 (5954): 32–36. Bibcode:1984Natur.308...32A. doi:10.1038/308032a0. PMID 6322001.
71. Sabanay I, Arad T, Weiner S, Geiger B (September 1991). "Study of vitrified, unstained frozen tissue sections by cryoimmunoelectron microscopy". Journal of Cell Science. 100 (1): 227–236. doi:10.1242/jcs.100.1.227. PMID 1795028.
72. Kasas S, Dumas G, Dietler G, Catsicas S, Adrian M (July 2003). "Vitrification of cryoelectron microscopy specimens revealed by high-speed photographic imaging". Journal of Microscopy. 211 (Pt 1): 48–53. doi:10.1046/j.1365-2818.2003.01193.x. PMID 12839550.

External links

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• An Introduction to Microscopy Archived 2013-07-19 at the Wayback Machine: resources for teachers and students
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• Science Aid: Electron Microscopy:By Kaden park

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