Import CTFFIND4's CTF results (not CTF-corrected micrographs)

Hi All,

I am wondering what is the best way to import CTFFIND4 results to cryoSPARC. I have a dataset where each micrograph has a predicted aberration (defocus and stig) and phase shift. I would like to import the CTFFIND4 results for them. Because the prediction for each micrograph is unique, I can’t do this with cryoSPARC’s CTFFIND4. (If there is a way, I would love to know!) Can I get some hint on this or the way around this? Appreciate your help!

Yue

Hi Yue,

There is still no easy way to import micrographs with associated CTF parameters as far as I know. It would be very useful to have the capacity to import micrographs from star files, but this is not currently supported.

You can import particle star files though - so if you have picks, you could extract these in relion, and then import both the micrographs (with output constant CTF=true) and the particles. You can then re-extract from the micrographs as desired (as subsequent extractions will inherit CTF parameters from the particles).

I don’t think there is a way to copy CTF parameters from particle to micrograph, but perhaps it is possible using cryosparc-tools (in which case that might provide a solution in the event you want to repick inside cryoSPARC).

Cheers
Oli

Hi Oli,

Thank you so much for your insights! I see… I will probably go with your suggestions for Relion and come back to cryoSPARC if need.
Appreciate your help! Thanks!

Yue