Correcting for local and global motion in cryo-EM data.
During the collection of cryo-EM data, motion of the sample occurrs for various reasons. The sample as a whole may move (stage drift), or the sample may deform due to the energy deposited by the electron beam itself (anisotropic deformation). Correcting for this motion is the first step in the data processing pipeline.
CryoSPARC contains several Jobs for motion estimation and correction:
- Patch motion correction corrects for both stage drift and anisotropic motion, while requiring no prior knowledge of particle location. We recommend using patch motion correction as the default choice when processing new data.
- Full-frame motion correction corrects for stage drift only, treating the sample as rigid.
- Local motion correction uses prior knowledge about particle locations within the micrographs to do motion correction on individual particles. Occasionally this can result in higher resolution reconstructions than the use of patch motion correction alone. Since local motion correction requires particle locations, the typical use case is to go back and use local motion correction once picking is complete (having used patch or local motion correction for the initial processing).
- A wrapper for MotionCor2 is available.