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Crystal Recognition

XREC Copyright 2006-2010
European Molecular Biology Laboratory

Authors: Sudhir Babu Pothineni, Tilo Strutz, David Watts and Victor S. Lamzin

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XREC is a software suite for automated crystal recognition. It has two distinct modules, XREC for crystal centring on a beamline goniostat and FREC, for fluorescence-based analysis of crystallisation conditions.

XREC - Automated crystal centering

XREC processes a series of images, which display different orientations of a crystal flash-cooled in a loop. The software uses a number of different algorithms that are automatically combined to determine the crystal centre and provides the estimate of accuracy of the results. Please refer to the XREC Manual for details.

  • Pothineni SB, Strutz T & Lamzin VS (2006) Automated detection and centring of cryo-colled protein crystals. Acta Crystallogr D Biol Crystallogr. 62, 1358-1368. Abstract

    XREC has been designed to give accurate results regardless of the imaging conditions or type of loop used. To date XREC has been tested on a dataset of several hundred images from 5 different laboratories including images of crystals in nylon loops, LithoLoops© and MicroMounts©.

    We keep extending this database and therefore ask the user community to share their crystal images and configuration data files with us, so that we are able to keep improving the performance of XREC. Please contact David Watts to submit images for inclusion in the database.

    XREC crystal centering results on a 453 crystal image sequence test database

    FREC - Fluorescence based crystallisation plate analysis software

    FREC software has been designed for automated image analysis of crystallization experiments using fluorescence from trace amounts of a nonspecific dye. The fluorescence images obtained strongly contrast protein crystals against other phenomena, such as precipitation and phase separation. FREC is able to quantitatively evaluate the crystallization outcome based on a biophysical metric correlated with voxel protein concentration.

  • Watts D, Müller-Dieckmann J, Tsakanova G, Lamzin VS & Groves MR (2010). Quantitative evaluation of macromolecular crystallization experiments using 1,8-ANS Fluorescence, Acta Crystallographica Section D: Biological Crystallography, 2010, Volume D66, pages 901-908 download paper

    FREC webpage


    XREC 3.1 license and download
    Image gallery
    XREC Manual (pdf)
    XREC DLL Manual (pdf)

    The FREC Windows executable is available for download as part of the XREC distribution.

    Pages on this server are maintained by David Watts and Victor S. Lamzin. DW and VL accept full responsibility for the content of these pages, for which EMBL is not responsible by any means.

    This work was supported in part by the BIOXHIT project
    EC FP6 contract number LSHG-CT-2003-503420

    Last Edited: 02.07.2010