Unbinning particles using 'Downsample particles' job in CRYOSPARC

closed

#1

Hi
I have imported particles from RELION and binned them 2x in CRYOSPARC using the ‘Downsample particles’. Later I have done a classification scheme in CRYOSPARC on the binned particles. I have NOT imported the motion-corrected-micrographs from RELION. Is it possible to use ‘Downsample particles’ to unbin the particles after classifying them in CRYOSPARC?
I am using CRYOSPARC v2.5.0.

Thanks
Quereshi


#2

Hi @KutaQureshi,

Sorry for the delayed response - this may be too late and hopefully you have figured out a way forward in your project, but for reference - this is possible by simply connecting partial outputs from the classification results and the original particles together to the next refinement job. You do not need to explicitly “unbin” the particles, since the original particles are still present.
The steps would be as follows:

  1. connect the particles subset from your classification output to the input of the next refinement job
  2. In the job builder, you will see a small expansion dropdown beside the particle input group you just connected. Drop this down and you will see the low-level results that are contained in the particles (blob, ctf, alignments, locations, etc)
  3. Find the original imported particles, open up the import job and go to the “Outputs” tab
  4. From this outputs tab, select only the blob output of the particles, and connect this to the new refinement job from step 1, overriding the blob input that is already connected

Running the refinement job will do what you want, i.e. the original full size particles will be used, but only the subset of particles from your classification scheme.