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Progress towards an optimal specimen support for electron cryomicroscopy.

Russo CJ, Passmore LA - Curr. Opin. Struct. Biol. (2016)

Bottom Line: Supports are constructed to suspend biological samples within the vacuum of the electron microscope in a way that maximises image contrast.This includes the use of graphene as a surface for the adsorption of proteins and the design of an ultrastable, all-gold substrate that reduces the motion of molecules during electron irradiation.We discuss the implications of these and other recent improvements in specimen supports on resolution, and place them in the context of important developments in structure determination by cryo-EM.

View Article: PubMed Central - PubMed

Affiliation: MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK. Electronic address: crusso@mrc-lmb.cam.ac.uk.

No MeSH data available.


Related in: MedlinePlus

Design of cryo-EM specimen supports. Top view and section diagrams of typical specimen support geometries, comprising a perforated foil on a metal mesh grid. Sometimes an additional thin continuous film is added to the foil to change its surface properties. Three different magnifications are shown (a)–(c) along with lists of materials used for each component of the support. The most commonly used materials are in bold.
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fig0010: Design of cryo-EM specimen supports. Top view and section diagrams of typical specimen support geometries, comprising a perforated foil on a metal mesh grid. Sometimes an additional thin continuous film is added to the foil to change its surface properties. Three different magnifications are shown (a)–(c) along with lists of materials used for each component of the support. The most commonly used materials are in bold.

Mentions: To satisfy the physical constraints discussed above, support designs for biological cryo-EM have converged on a geometry that comprises a perforated foil suspended across a 3 mm grid (Figure 2). Macromolecules in vitrified aqueous solution are suspended across the holes. This use of perforated (not continuous) foils means that samples can be imaged without additional background signal from the support material. This geometry also allows focusing and other parameters to be set using an adjacent area of the support foil. Perforated foils can have holes with a random size distribution, in an irregular arrangement (holey or lacey grids) [34, 35, 36]. More recently, foils with regular arrays of holes of controlled size have been made using micro-fabrication techniques (e.g. Quantifoils® or C-flatsTM [37•, 38, 39, 40]), allowing more reproducible specimen preparation and imaging, and facilitating easier low-dose data collection.


Progress towards an optimal specimen support for electron cryomicroscopy.

Russo CJ, Passmore LA - Curr. Opin. Struct. Biol. (2016)

Design of cryo-EM specimen supports. Top view and section diagrams of typical specimen support geometries, comprising a perforated foil on a metal mesh grid. Sometimes an additional thin continuous film is added to the foil to change its surface properties. Three different magnifications are shown (a)–(c) along with lists of materials used for each component of the support. The most commonly used materials are in bold.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4863039&req=5

fig0010: Design of cryo-EM specimen supports. Top view and section diagrams of typical specimen support geometries, comprising a perforated foil on a metal mesh grid. Sometimes an additional thin continuous film is added to the foil to change its surface properties. Three different magnifications are shown (a)–(c) along with lists of materials used for each component of the support. The most commonly used materials are in bold.
Mentions: To satisfy the physical constraints discussed above, support designs for biological cryo-EM have converged on a geometry that comprises a perforated foil suspended across a 3 mm grid (Figure 2). Macromolecules in vitrified aqueous solution are suspended across the holes. This use of perforated (not continuous) foils means that samples can be imaged without additional background signal from the support material. This geometry also allows focusing and other parameters to be set using an adjacent area of the support foil. Perforated foils can have holes with a random size distribution, in an irregular arrangement (holey or lacey grids) [34, 35, 36]. More recently, foils with regular arrays of holes of controlled size have been made using micro-fabrication techniques (e.g. Quantifoils® or C-flatsTM [37•, 38, 39, 40]), allowing more reproducible specimen preparation and imaging, and facilitating easier low-dose data collection.

Bottom Line: Supports are constructed to suspend biological samples within the vacuum of the electron microscope in a way that maximises image contrast.This includes the use of graphene as a surface for the adsorption of proteins and the design of an ultrastable, all-gold substrate that reduces the motion of molecules during electron irradiation.We discuss the implications of these and other recent improvements in specimen supports on resolution, and place them in the context of important developments in structure determination by cryo-EM.

View Article: PubMed Central - PubMed

Affiliation: MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK. Electronic address: crusso@mrc-lmb.cam.ac.uk.

No MeSH data available.


Related in: MedlinePlus