WikiSysop: Created page with "== Citation == S. Khavnekar and W. Wan, “An approach for coherent periodogram averaging of tilt-series data for improved contrast transfer function estimation,” FEBS Open Bio, 2025. == Abstract == Cryo-electron microscopy (cryo-EM) has become an indispensable technique for determining three-dimensional structures of biological macromolecules. A critical aspect of achieving high-resolution cryo-EM reconstructions is accurately determining and correcting for the mic..."

2025-06-20T10:13:57Z

Created page with "== Citation == S. Khavnekar and W. Wan, “An approach for coherent periodogram averaging of tilt-series data for improved contrast transfer function estimation,” FEBS Open Bio, 2025. == Abstract == Cryo-electron microscopy (cryo-EM) has become an indispensable technique for determining three-dimensional structures of biological macromolecules. A critical aspect of achieving high-resolution cryo-EM reconstructions is accurately determining and correcting for the mic..."

New page

== Citation ==

S. Khavnekar and W. Wan, “An approach for coherent periodogram averaging of tilt-series data for improved contrast transfer function estimation,” FEBS Open Bio, 2025.

== Abstract ==

Cryo-electron microscopy (cryo-EM) has become an indispensable technique
for determining three-dimensional structures of biological macromolecules.
A critical aspect of achieving high-resolution cryo-EM
reconstructions is accurately determining and correcting for the microscope’s
contrast transfer function (CTF). The CTF introduces
defocus-dependent distortions during imaging; if not properly accounted
for, the CTF can distort features in and limit the resolution of 3D reconstructions.
For tilt-series data used in cryo-electron tomography (cryo-ET),
CTF estimation becomes even more challenging due to the tilt of the specimen,
which introduces a defocus gradient across the field of view, as well
as the low dose and signal in individual tilt images. Here, we describe a
simple algorithm to improve the accuracy of CTF estimation of tilted
images by leveraging the tilt-series alignment parameters determined for
tomographic reconstruction to explicitly account for the tilted specimen
geometry. In brief, each tilt image is divided into patches, each of which
are then stretched according to their defocus shift. These are then summed
to provide a coherent power spectrum at the tilt axis, which can then be
used in standard CTF estimation algorithms. This uses all the data in each
image to enhance the visibility of Thon rings, thereby improving
high-resolution CTF estimation and subsequent enhancements in the resolution
of subtomogram averages.

== Keywords ==

== Links ==

https://febs.onlinelibrary.wiley.com/doi/full/10.1002/2211-5463.70050

== Related software ==

== Related methods ==

== Comments ==

2025Khavnekar PSD - Revision history