title: TakeTwo: an indexing algorithm suited to still images with known crystal parameters.
abstract: The indexing methods currently used for serial femtosecond crystallography were originally developed for experiments in which crystals are rotated in the X-ray beam, providing significant three-dimensional information. On the other hand, shots from both X-ray free-electron lasers and serial synchrotron crystallography experiments are still images, in which the few three-dimensional data available arise only from the curvature of the Ewald sphere. Traditional synchrotron crystallography methods are thus less well suited to still image data processing. Here, a new indexing method is presented with the aim of maximizing information use from a still image given the known unit-cell dimensions and space group. Efficacy for cubic, hexagonal and orthorhombic space groups is shown, and for those showing some evidence of diffraction the indexing rate ranged from 90% (hexagonal space group) to 151% (cubic space group). Here, the indexing rate refers to the number of lattices indexed per image.
authors.affiliation: Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, England.
authors.forename: Helen Mary
authors.initials: HM
authors.lastname: Ginn
authors.affiliation: Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22607 Hamburg, Germany.
authors.forename: Philip
authors.initials: P
authors.lastname: Roedig
authors.affiliation: Department of Biochemistry, University of Toronto, King's College Circle, Toronto, ON M5S 1A8, Canada.
authors.forename: Anling
authors.initials: A
authors.lastname: Kuo
authors.affiliation: Diamond House, Harwell Science and Innovation Campus, Fermi Avenue, Didcot OX11 0QX, England.
authors.forename: Gwyndaf
authors.initials: G
authors.lastname: Evans
authors.affiliation: Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
authors.forename: Nicholas K
authors.initials: NK
authors.lastname: Sauter
authors.affiliation: Department of Biochemistry, University of Toronto, King's College Circle, Toronto, ON M5S 1A8, Canada.
authors.forename: Oliver P
authors.initials: OP
authors.lastname: Ernst
authors.affiliation: Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22607 Hamburg, Germany.
authors.forename: Alke
authors.initials: A
authors.lastname: Meents
authors.affiliation: Department of Biochemistry, University of Toronto, King's College Circle, Toronto, ON M5S 1A8, Canada.
authors.forename: Henrike
authors.initials: H
authors.lastname: Mueller-Werkmeister
authors.affiliation: Atomically Resolved Dynamics, Max-Planck-Institute for Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg, Germany.
authors.forename: R J Dwayne
authors.initials: RJ
authors.lastname: Miller
authors.affiliation: Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, England.
authors.forename: David Ian
authors.initials: DI
authors.lastname: Stuart
mesh_terms: D000465:Algorithms; D003461:Crystallography / Q000379:methods*; D018360:Crystallography, X-Ray / Q000379:methods; D004583:Electrons; D007834:Lasers; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D017356:Synchrotrons; D013997:Time Factors; D014965:X-Rays
chemical_list: D011506:Proteins
keywords: TakeTwo; X-ray free-electron lasers; XFELs; data processing; serial crystallography