Job: Blob Picker

Blob-based picking.

Description

• Automatically picks particles by searching for Gaussian signals.

Input

• Aligned/motion-corrected micrographs

Common Parameters

• The Minimum and Maximum particle diameters (A) to pick are required to use the blob picker. It is recommended to underestimate the minimum diameter and overestimate the maximum diameter.

• Pick on denoised micrographs: By default, Blob Picker will pick particles on raw micrographs even if denoised micrographs are available. Turning this parameter on will pick particles using the denoised micrographs. This may be helpful if there contrast is very poor. Regardless of this setting, particles will ultimately be extracted from the raw micrographs.

Output

• Particles

Notes and Limitations

Blob picking is a fast picking method but is generally the least accurate. This accuracy issue stems from being overambitious in micrographs featuring Gaussian shaped particles, and performing poorly on micrographs that lack Gaussian-like particles. The former is caused by the blob picker picking all Gaussians, regardless of whether they are particles or not. However, the incorrect particles can be filtered using a combination of the 2D Classification and Select 2D jobs.

Common Next Steps

• 2D Classification and Select 2D to generate templates for Template picking