AUTHOR=Kazan Ramy , Bourgeois Gabrielle , Carisetti Dominique , Florea Ileana , Larquet Eric , Maurice Jean-Luc , Mechulam Yves , Ozanam François , Schmitt Emmanuelle , Coureux Pierre-Damien TITLE=Grid batch-dependent tuning of glow discharge parameters JOURNAL=Frontiers in Molecular Biosciences VOLUME=9 YEAR=2022 URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2022.910218 DOI=10.3389/fmolb.2022.910218 ISSN=2296-889X ABSTRACT=

Sample preparation on cryo-EM grids can give various results, from very thin ice and homogeneous particle distribution (ideal case) to unwanted behavior such as particles around the “holes” or complexes that do not entirely correspond to the one in solution (real life). We recently run into such a case and finally found out that variations in the 3D reconstructions were systematically correlated with the grid batches that were used. We report the use of several techniques to investigate the grids' characteristics, namely TEM, SEM, Auger spectroscopy and Infrared Interferometry. This allowed us to diagnose the origin of grid preparation problems and to adjust glow discharge parameters. The methods used for each approach are described and the results obtained on a common specific case are reported.