Was this crystal shot frozen? With new crystals it is always a good idea to take some room temperature shots first to get an idea of how good the diffraction could possibly be. If you shoot the crystals at room temperature and the spots look fine, then the obvious answer is to optimize the freezing. If this is the case, one thing often worked for me is to add a little cryoprotectant to the crystal growth condition. Or if you are lucky, grow the crystal with the full-strength cryoprotectant. This can often reduce the stress on the crystal cause by the soaking in the cryoprotectant solution.
From: lysudiezhang1985 Sent: Wednesday, March 07, 2012 9:45 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] X-ray diffraction spot Hi Everyone, Thank you for help. Recently I get a crystal of my protein , but have poor diffraction data. The problem is that , just like I show you in the attachment, many of the diffraction spots look like the comet, who has a long tail. I wonder to know the reason for this , or some advice about what to do with this kind of data , how to optimize my crystal to improve the diffraction data. Thanks and have a good day.
