Quantifoil® is a holey carbon film with a special geometry and a thickness of about 12 nm, that is applied on a standard copper electron microscopy grid and provides an ideal support for biological samples in cryo-EM techniques^[1-8]. Higher mesh numbers (300) indicate closely spaced bars and provide higher stability, whereas lower numbers (200) provide larger free faces. The Quantifoil® carbon film has circular holes of defined size and interspace, e.g. R 2/1 (pictured) has holes of 2 µm diameter with an interspace of 1 µm in both dimensions.
The C2 versions on this page provide an additional 2 nm continuous carbon layer on top.

Selected Recent Literature Citations of Quantifoil®

[1] Lee et al. (2019) Cryo-EM Structures of the Hsp104 Protein Disaggregase Captured in the ATP Conformation. Cell Reports 26:29.
[2] Azubel et al. (2019) FGF21 trafficking in intact human cells revealed by cryo-electron tomography with gold nanoparticles. eLife DOI:10.7554/eLife.43146.
[3] Zhao et al. (2018) Structure and mechanogating mechanism of the Piezo1 channel. Nature 554:487.
[4] Wijnands et al. (2018) Controlling protein activity by dynamic recruitmenton a supramolecular polymer platform. Nat. Commun. 9:65.
[5] Ke et al. (2018) Promotion of virus assembly and organization by the measles virus matrix protein. Nat. Commun. 9:1736.
[6] Zhang et al. (2018) Molecular structure of the ATP-bound, phosphorylated human CFTR. PNAS 115:12757.
[7] Park et al. (2017) Structure of a CLC chloride ion channel by cryo-electron microscopy. Nature 541:500.
[8] Ekiert et al. (2017) Architectures of Lipid Transport Systems for the Bacterial Outer Membrane. Cell 169:273.