The helical data collection option in MXCuBE allows the user to mitigate the effects of radiation damage to some extent by constantly exposing a new part of the crystal during the collection of a data set.  This is most commonly used on the beamlines ID23-2 and ID29 where the beamsize is much smaller than most samples; however, the option exists on all beamlines and has been used sucessfully with "larger beams" of 100 microns in diameter.

 

Please cite Flot, D., et al (2010) The ID23-2 structural biology microfocus beamline at the ESRF. J. Synch. Rad., 17., 107-118, for any experiments that used the helical data collection protocols.

 

 

 

 

The helical data collection protocol is best used on "needle" shaped crystals over areas with reasonably homogeneous diffraction quality, but can be used on all samples.  The principles are simple:

  • Calculate a data collection strategy using EDNA or your preferred software package
  • Define an "end" and "start" centering point on the crystal to define the line of translation during the oscillation
  • The distance between the points is then divided by the total rotation range of the strategy in order to have a number of steps across the crystal on which to collect a wedge of data.