EasyGrid: A versatile platform for automated cryo-EM sample preparation and quality control

Gemin, O.; Armijo, V.; Hons, M.; Bissardon, C.; Linares, R.; Bowler, M. W.; Wolff, G.; Kovalev, K.; Babenko, A.; Salo, V. T.; Schneider, S.; Rossi, C.; Lecomte, L.; Deckers, T.; Lauzier, K.; Janocha, R.; Felisaz, F.; Sinoir, J.; Galej, W. P.; Mahamid, J.; Muller, C. W.; Eustermann, S.; Mattei, S.; Cipriani, F.; Papp, G.

doi:10.1101/2024.01.18.576170

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bioRxiv · 10.1101/2024.01.18.576170

EasyGrid: A versatile platform for automated cryo-EM sample preparation and quality control

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Abstract

Imaging biological macromolecules in their native state with single-particle cryo-electron microscopy (cryo-EM) or in situ cryo-electron tomography (cryo-ET) requires optimized approaches for the preparation and vitrification of biological samples. Here, we describe EasyGrid, a versatile technology enabling systematic, tailored and advanced sample preparation for cellular and structural biology. This automated, standalone platform combines in-line plasma treatment, microfluidic dispensing, blot-less sample spreading, jet-based vitrification and on-the-fly grid quality control using light interferometry to streamline cryo-EM sample optimization. With EasyGrid, we optimized grid preparation for different purified macromolecular complexes and subsequently determined their structure with cryo-EM. We also demonstrated how the platform allows better vitrification of large, mammalian cells compared to standard plunge-freezing. Automated sample preparation with EasyGrid establishes an advanced, high-throughput platform for both single-particle cryo-EM and cellular cryo-ET sample preparation.

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Gemin, O., Armijo, V., Hons, M., Bissardon, C., Linares, R., Bowler, M. W., Wolff, G., Kovalev, K., Babenko, A., Salo, V. T., Schneider, S., Rossi, C., Lecomte, L., Deckers, T., Lauzier, K., Janocha, R., Felisaz, F., Sinoir, J., Galej, W. P., Mahamid, J., Muller, C. W., Eustermann, S., Mattei, S., Cipriani, F., Papp, G.. 2024-01-20. EasyGrid: A versatile platform for automated cryo-EM sample preparation and quality control. https://doi.org/10.1101/2024.01.18.576170

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