Additional Ultrathin Continuous Carbon Layer
An ultrathin (2-3 nm) carbon layer applied to grids is widely recommended to improve particle distribution1,2,3 and has been shown to improve data quality when applied to both QUANTIFOIL® 4 Holey Carbon Films and UltrAuFoil® 5 Gold Supports. Shown on the right 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 the improved 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.
An additional carbon layer can be added to most QUANTIFOIL® holey carbon film support 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. If you are interested in adding an ultrathin carbon layer to UltrAuFoil® gold supports, please contact us for further details.
- Passmore, LA and Russo, CJ. Methods Enzymol. 579: 51-86 (2016).
- Drulyte, I et al. Acta Cryst D74: 560-571 (2018).
- Thompson, RF et al. Methods 100: 3-15 (2016).
- Rawson, S et al. Structure 23: 461-471 (2015).
- Russo, CJ and Passmore, LA. J. Struct. Biol. 193:33-44 (2016).
- Leidreiter, F et al. Sci. Adv. 5: eaax6497 (2019).