[ccp4bb]: Radiation damage problem

[Uhnsoo Cho]

Dear bulletin members,   Sorry for non-CCP4 related questions. Recently, I've got crystals which have a radiation damage problem. It also has a weak diffraction because of the big unit cell dimension (about 300A in one direction), so I have to overexpose crystals even with the synchrotron beam. The problem is that during the data collection, the resolution decaded gradually from 3 to 6A after certain number of frames (about 30 or 40 frames). Do you have any experiences or any suggestions that I can evade this radiation damage? Any suggestions will be grateful. Thank you.   Best regards,   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Uhn-Soo,Cho Graduate student in Biological Structure Department University of Washington. HSB G514 1959 NE Pacific St. Seattle, WA 98195-7420 Box. 357420 Fax #206-543-1524 Tel # 206-221-2435 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~