XREC Copyright 2006-2010
European Molecular Biology Laboratory
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.
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©
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
Acta Crystallographica Section D: Biological Crystallography, 2010,
Volume D66, pages 901-908 download paper
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