Hi,
I am trying to find a cryoprotectant for some crystals which seem to be
rather sensitive. These crystals formed from a protein solution
(10mg/mL) in 10mM NaAcetate pH 4.5 buffer with no precipitant at 4C in an
eppendorf tube. They're not very nice looking crystals, but they
diffract quite well.
I've found that the crystals are very stable in 15-18% PEG 10K with 10mM
NaAcetate pH 4.5 and diffract well even after incubation in this
stabilization solution for 2 to 3 days. Unfortunately, the crystal
decays in a capillary in the X-ray beam at room temperature and has a
tendency to liquify in a capillary kept at 4C in the cryostream (possibly
due to condensation).
I have been trying to find a cryoprotectant for this crystal. I have
tried glycerol, ethylene glycol, sucrose, glucose, PEG 400, MPD,
1,6-hexanediol, and a mixture of ethylene glycol and glycerol. They
either crack the crystal or greatly increase mosaicity and decrease
resolution.
If anyone can offer some suggestioins, please e-mail me at:
dan at crystal.biochem.queensu.ca
Thanks in advance.
Dan
