Not that all proteins are created alike, but we had a protein
crystallize in a similar situation (PEG/20%IPA). I don't remember the
exact details, but we did have good luck using just glycerol as a
cryoprotectant. That is, I made up the well buffer and added to that
well buffer 20-25% glycerol (in addition to IPA/PEG), and moved the
crystal into that. We had no issues with cracking or anything, and data
collection went well. The first thing I tried worked, so I don't have a
lot of trial information for you. You could probably reduce the
glycerol a bit with no worries, but I don't know.
Good luck
Dave
shivesh kumar wrote:
> Dear all,
> The question is regarding the cryoprotectant.We have crystallized a
> protein in 20% PEG 500 with 10% isopropanol.What should be the cryo we
> should try for data collection.Also,what percentage of PEG 500 is
> sufficient enough as a cryo for data collection.
> We are also trying to crystallize it with higher PEG's also like 1K,
> 2K, 4K.Lets C.Since the condition is having isopropanol also and it is
> reported that mounting with isoprop is very difficult and it
> evaporates as soon as we open the slides.
> Thanx in advance...
> Shivesh Kumar
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