Hi all, I found some microcrystals the other day in some trays grown at 4C. Strangely enough, they disappeared the next day after putting them back in the fridge overnight, but after letting the tray sit at RT for 5-10 min, the microcrystals reappeared. Leaving them at RT for 2-3 hrs, and then the crystals disappear. These small crystals took about 3 months before I saw them, so i doubted that they were salt, but it's exhibiting very odd behavior. Has anyone seen anything like this before?
The condition was: 0.2M NaF, 20% w/v PEG 3350, pH7.3 Protein was at 10mg/ml, 20mM Tris, 150mM NaCl, 5mM DTT, pH8.0. Thanks in advance for any thoughts on the matter. Peter Hsu