Additional Ultrathin Continuous Carbon Layer


Particle density and distribution has been widely shown to improve on the addition of an ultrathin (2-3 nm) carbon (UTC) layer to a grid1,2,3. Data quality has improved for both QUANTIFOIL® 4 Holey Carbon Films and UltrAuFoil® 5 Gold Supports when a UTC layer is applied. 

An additional UTC layer can be added to most QUANTIFOIL® Holey Carbon Film supports on request. The most popular thickness is 2 nm, but thicker, more stable, 3 and 5 nm layers are also available, and even 10 nm is possible. For an additional UTC on QUANTIFOIL® Holey Carbon Film supports, please request a quote.  Alternatively, if you are interested in adding a UTC layer to UltrAuFoil® Holey Gold supports, please contact us for further details.

As the ultrathin Carbon layer may not be as stable as our usual films, we recommend using grids with a UTC layer within 6 months of delivery.

Improvements in specimen quality

Shown in the image is the structure of Photorhabdus luminescens TcdA1, a large multisubunit complex toxin, with activity against insects, whose structure was determined using images collected on QUANTIFOIL® R 2/1 grids with a 2 nm additional carbon layer6. Many biomolecules have a strong affinity for carbon, and a number of factors contribute to a resulting improvement in specimen quality:

  • Increased numbers of particles due to adsorption of biomolecules onto carbon prior to blotting.
  • Improved particle distribution due to interaction with carbon surface across the hole.
  • Reduction in the number of particles adopting a preferred orientation.



The use of an additional ultrathin layer of Carbon is a well-established method to improve particle dispersion, and other recent examples include:

Zhao et al. Regulation of translation by ribosomal RNA pseudouridylation. Sci Adv 9: eadg8190 (2023)

Zheng et al. Cryo-EM and femtosecond spectroscopic studies provide mechanistic insight into the energy transfer in CpcL-phycobilisomes. Nat. Commun. 14: 3961 (2023)

Download list of publications mentioning additional Carbon layer