[3dem] FT artefacts from EPU .mrc files

[Kizziah, James]

Hello all,

I am observing bizarre artefacts-vertical streaks and arrays of spots (attached)-in Fourier transforms calculated from EPU's averaged .mrc files during CTF estimation with Gctf v1.06 (via RELION-3.1.0). With Ctffind or after conversion to and from EMAN2's .hdf format, all seems normal.

Is there a known incompatibility between EPU's .mrc format and Gctf, or could these artefacts be caused by something else? Are there any alternative solutions to converting to and from .hdf?

Thank you,

James L. Kizziah, PhD | Cryo-EM Facility Manager
Department of Microbiology
UAB | The University of Alabama at Birmingham
SHEL B40 | 1825 University Blvd | Birmingham, AL 35233
kizziah4 at uab.edu<mailto:kizziah4 at uab.edu> | Phone: (205) 975-3376 | Pronouns: he/him/his
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