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upstart writes in with an IRC submission for RandomFactor:

New algorithm sharpens focus of world's most powerful microscopes:

For decades, [...] cryo-EM [*] maps—generated by taking many microscopy images and applying image-processing software—have been a crucial tool for researchers seeking to learn how the molecules within animals, plants, microbes, and viruses function. And in recent years, cryo-EM technology has advanced to the point that it can produce structures with atomic-level resolution for many types of molecules. Yet in some situations, even the most sophisticated cryo-EM methods still generate maps with lower resolution and greater uncertainty than required to tease out the details of complex chemical reactions.

[...] The algorithm sharpens molecular maps by filtering the data based on existing knowledge of what molecules look like and how to best estimate and remove noise (unwanted and irrelevant data) in microscopy data. An approach with the same theoretical basis was previously used to improve structure maps generated from X-ray crystallography, and scientists have proposed its use in cryo-EM before. But, according to Adams, no one had been able to show definitive evidence that it worked for cryo-EM until now.

The team [...] first applied the algorithm to a publicly available map of the human protein apoferritin that is known to have 3.1-angstrom resolution (an angstrom is equal to a 10-billionth of a meter; for reference, the diameter of a carbon atom is estimated to be 2 angstroms). Then, they compared their enhanced version to another publicly available apoferritin reference map with 1.8-angstrom resolution, and found improved correlation between the two.

[*] cryo-EM: Cryogenic electron microscopy.

Journal Reference:
Thomas C. Terwilliger, Steven J. Ludtke, Randy J. Read, et al. Improvement of cryo-EM maps by density modification, Nature Methods (DOI: 10.1038/s41592-020-0914-9)

Original Submission