[ccp4bb]: big crystals that diffrct poorly

[Christopher Lehmann <lehmann@umbi.umd.edu>]

Dear Jay, 

the (diffraction) quality of a crystal is sometimes correlated with its solvent contend. 
Robert  Huber advertise a so called free mounting system for improving of protein crystals. 
It is an humidity regulating device. 

Huxley, H. E. & Kendrew, J. C. (1952).Acta Cryst., 6, 76-80. 
Kiefersauer, R., Stetefeld, J., Gomis-Rüth, F. X., Romao, M. J., Lottspeich, F. & Huber, R., in preparation 

we had cases that diffraction could be improved by annealing. This was correlated with unit cell shrinking, 
so it is probably also the loss of water that improved the diffraction. this methods has unfortunately 
problems with its reproducibility. 

Bunick, G. Harp, J. Tim, D. and Hanson, L. Macromolecular crystal annealing. (1998), The Rigaku Journal, Vol15, 6-10. 

There is additionally a method called MPD-annealing. 

Good luck 
(:hristopher 
  
  
  
  

Jay Pandit wrote: 

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  Hello all, 
   Everyone has probably experienced this - big (0.5mmx0.5mmx0.3mm), 
  beautiful crystals (sharp edges, clean faces), that diffract strongly to 
  6A, and no further. What's the reason for this ? Are there any stories 
  out there of tricks that have improved the resolution of such crystals ? 
  This is not a ccp4-related topic, but then this bb is the best general 
  crystallography discussion group that there is, so I have to post this 
  question here ... 
   Jay 
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   Jay Pandit 
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