Quantifoil & C-Flat perfect holey carbon films

QUANTIFOIL® holey carbon films are produced by a semiconductor lithographic process. They are available with different hole sizes, shapes and arrangements. Researchers who would like to try out different types of QUANTIFOIL® holey films in order to find out which one meets their requirements best, can order our MixBox. QUANTIFOIL® R 1/4 may be preferred over R 1.2/1.3 when an increased tolerance with respect to the position of beam and a larger beam diameter are desired, such as in the case with automated image acquisition. QUANTIFOIL® provide a high percentage of open area in addition to minimising total specimen thickness. The thickness of the foil is about 20nm, although only 10nm of carbon is evaporated onto the plastic. The surface properties of QUANTIFOIL® holey carbon support film, especially the wetting properties, may have to be adapted according to one’s particular requirements. Untreated ageing QUANTIFOIL® tends to be hydrophobic. The foil can be made hydrophilic by glow discharging in residual air or by metal coating. QUANTIFOIL® grids are packaged with their coated sides toward the centre of the grid box.. Holey films with new geometric parameters can be designed. In addition, they can be delivered with coatings other than carbon that can be deposited by vacuum evaporation. QUANTIFOIL® with circular holes is mainly used in cryo-EM. The roundness of the holes is advantageous for the formation of an ice layer of constant thickness. The hole size that is chosen depends on the magnification used and on whether or not one wishes to include a support film in the image. Assessment of the image quality is easier when foil is included in the picture as the power spectrum of a foil is stronger than that of unsupported ice.