Characterization Standard for In-situ Cryo-electron Tomography

Ali, M.; Hutchings, J.; Dutta, T.; Jean, N.; Greenan, G.; Montabana, E. A.; Schwartz, J.; Finn, M. G.; Haury, M.; Agard, D.; Carragher, B.; Kopylov, M.; Paraan, M.

doi:10.64898/2026.05.20.726049

bioRxiv · 10.64898/2026.05.20.726049

Characterization Standard for In-situ Cryo-electron Tomography

Ali, M.·Hutchings, J.·Dutta, T.·Jean, N.·Greenan, G.·Montabana, E. A.·Schwartz, J.·Finn, M. G.·Haury, M.·Agard, D.·Carragher, B.·Kopylov, M.·Paraan, M.

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Abstract

Standardized biological specimens are essential for optimizing cryoEM workflows and benchmarking instrument performance. While apoferritin fulfills this role for single-particle analysis, no equivalent exists for cryo-electron tomography. Ribosomes are frequently used but require large datasets due to C1 symmetry and structural heterogeneity, limiting rapid optimization and standardized comparison of workflows. Here, we present PP7 virus-like particles (VLPs) overexpressed in E. coli as a scalable in situ benchmark. VLPs have high orders of symmetry enabling rapid, high-resolution validation of tomographic pipelines from minimal datasets, while their distinct structural features across low to high resolutions provide a practical resolution metric.

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Ali, M., Hutchings, J., Dutta, T., Jean, N., Greenan, G., Montabana, E. A., Schwartz, J., Finn, M. G., Haury, M., Agard, D., Carragher, B., Kopylov, M., Paraan, M.. 2026-05-22. Characterization Standard for In-situ Cryo-electron Tomography. https://doi.org/10.64898/2026.05.20.726049

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