Hello Claudia,
Under what conditions did the crystals grow? If its sodium acetate and
ammonium sulphate I would try adding sodium malonate as a cryo
protectant (with 2-2.3M ammonium sulphate adding 0.6-0.8M Na malonate
should be sufficient) or increasing the ammonium sulphate concentration.
Sabine
Claudia Scotti wrote:
Dear list,
I'm trying to freeze crystals in cryoconditions containing the following:
0.1 M Sodium acetate pH 4.4
2.15-2.3 M Ammonium sulphate
7% n-butanol
15% glycerol
The problem is that the crystals (beautiful hexagonal prisms) seem to
shatter in a random fashion: some are unaffected, some, coming from
the same drop, disgregate miserably. One even split into three parts,
of which two disgregated and one survived perfectly well.
I've tried both by moving the crystals directly in the cryocondition
and by progressively increasing the glycerol concentration to no avail.
Shall I just select those that survive?
I was wondering if anybody has ever had this same problem and
if freezing under oil could be an alternative. If yes: any suggestions
on how to fish the crystals? I tried it in the past, but I found it
very difficult...
Experiences and suggestions are welcome.
Claudia
Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di
Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia
Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673
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Dr. Sabine Schneider
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