Semi-automated selection of cryo-EM particles in RELION-1.3.
Bottom Line: Here, a semi-automated particle selection procedure is presented that has been implemented within the open-source software RELION.With only limited user-interaction, the proposed procedure yields results that are comparable to manual particle selection.Together with an improved graphical user interface, these developments further contribute to turning RELION from a stand-alone refinement program into a convenient image processing pipeline for the entire single-particle approach.
Affiliation: MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK. Electronic address: email@example.com.Show MeSH
Mentions: Apart from the new algorithms described above, RELION-1.3 also features an improved graphical user-interface (GUI). Whereas previous releases still relied on user input from the command-line, e.g. using linux-based “awk” commands to select particles from specific classes, all of the functionalities described in this paper may now be performed from the GUI. To that purpose, a new image display program has been developed that reads the RELION-specific metadata files in STAR format (Hall, 1991). This provides the user with a convenient tool to manually inspect micrographs and pick particles, display extracted particles in a given order, write out STAR files with particles from a selection of classes, or display aligned particles from any given class. Fig. 2 shows a screen shot of the new interface, as well as a schematic of the proposed semi-automated particle selection procedure that links together the auto-picking, sorting and reference-free 2D class averaging algorithms (Scheres, 2012b).
Affiliation: MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK. Electronic address: firstname.lastname@example.org.