QUANTIFOIL® Holey Carbon Grids for Cryo TEM

EMS Catalog #Q225CR-06

Quantifoil perforated support foils are used as support films on TEM grids – when compared to conventional holey carbon support films, they are more beneficial for numerous applications from conventional transmission electron microscopy (TEM) to low-energy point source (LEEPS) microscopy.

Quantifoils are manufactured with specifically pre-defined shape, hole size and arrangement. The perforated foil can be used to directly support large specimens, such as a micron-sized powder particle, or as a support film for a sample on an ultra-thin carbon support foil. Using the Quanitfoill® for direct support can be valuable in many spectroscopies such as electron spectroscopic and dark field imaging, electron diffraction (ED), and electron energy loss spectroscopy (EELS). It is even useful for biomacromolecular complexes, which are observed in a free-hanging layer of medium.

There is virtually no thickness variation across the carbon film as it is produced precisely within 10-12nm. Note that with carbon film there is a possibility for a thin carbon layer of less than 20nm that can be a production remnant. The holes, however, are guaranteed to be clean and free of any polymer film. You can rest assured there is nothing other than the sample in the electron beam path as you collect data from a sample that is over a hole.

For secure shipping, Quantifoil holey carbon grids are meticulously packed in storage boxes with the carbon film side facing the center of the grid box and the holey carbon film on the dull side of the grid.

Please note that Electron Microscopies Sciences offers a wide variety of Quantifoil grids in several designs: Circular Holes, Square Holes, Hexagonal Holes and "Multi A" Holes. Refer to Tables 1-3 for specifications on the grids available. Following are brief descriptions of each grid type:

Table 1

Table 2

Table 3

Circular Holes

For Cryo TEM applications the Quantifoil with circular holes is recommended. The round aspect of the holes is expedient with respect to the formation of an ice layer of uniform thickness. The hole spacing of choices is dependent upon magnification and whether or not one wishes to include evidence of support in the final image. Note that due to the strong nature of the power spectrum of the foil compared to the unsupported ice, image quality assessment is best reached when the foil is included in the final image.

Furthermore, for magnifications in the range of 30,000x to 40,000x, Quantifoil holey films with 2 and 1.2µm circular holes are preferred. When using automated image acquisition or a larger beam diameter is used, Quantifoil R 2/4 is more often recommended than R 2/2.

See Table 1 for Individual Grid Specifications
Quantifoil R 2/1	Quantifoil R 2/2	Quantifoil R 2/4
Quantifoil R 1.2/1.3	Quantifoil R 1/4	Quantifoil R 3.5/1

Square Holes

See Table 2 for Grid Specifications

Quantifoil S 7/2

When working in TEM applications, Quantifoil with square mesh holes provide best results. Carbon film, on the other hand, is typically too thin to be used with this type of application. When samples are larger than the 7x7 mm holes, and mechanical stability and maximum open area are needed, the Quantifoil® S7/2 delivers.

The Quantifoil holey films are available on standard, stock grid meshes – 200, 300, 400 and 100 x 400 mesh – in Au, Ni, Cu and Rh plated Cu. Special orders are also possible with other grid construction and meshes.

The Quantifoil S 7/2 pattern also available for the Multi-Slot TEM grid, in Cu and Ni.

Note: The Quantifoil S 7/2 pattern is supported with a Formvar film for whole specimen stability.

Hexagonal Holes

See Table 2 for Grid Specifications

Quantifoil Hex 15

Quantifoil Hexagonal Geometry was developed for use with TEM slot grid, especially for supporting serial thin sections. The 0.5 x 2 mm slot grids have great mechanical stability in addition to maximum support-free areas.

Designed specifically for TEM slot grids, Quantifoil Hexagonal Geometry supports thin serial sections. This allows for the visualization and interpretation of sections that lie on the carbon bars (not the grid bars).

Multi A Holey Films

See Table 3 for Grid Specifications

Quantifoil Multi A

Quantifoil Multi A Magnified

The Quantifoil Multi A support film has a repetitive pattern of holes of unique shapes and sizes. The circular holes have three different diameters, with different spacings. There are also oval holes that appear round when used with tilts of ~70° or better.

Grid construction:

• Circular hole diameters are approximately 1, 1.4, and 2 mm
• *Bar width ranges are 0.5 to 4 mm
• Oval holes are 8 x 2 mm and 4 x 1 mm

*Bar width refers to the distanced covered on the carbon film from the edge of one hole to its nearest neighbor hole.

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