[ccp4bb]: a crystal moubting problem

[Alan Tunnicliffe <atunni@imb-jena.de>]

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Hi Guan

How do you want to collect your data, room temperature or 100K ?
Here is a technique which may help in either case.

Before trying to remove any crystals from your drop, 
try covering the whole drop with parafin oil, then
remove the crystal from the drop as normal using a cryo-loop. 
The crystal has to pass through the layer of
oil and as such will also be coated with the oil. 
In this case the parafin oil serves a number of purposes,
it will help prevent/slow down the loss of the alcohol 
by evaporation, and will prevent the growth of small
ammonium sulphate crystals which can occur on crystal transfer.

The crystal mounted in the loop can now be transfered to nitrogen 
gas at 100K or liquid nitrogen, to store the crystal for later 
collection. 

More information on this technique can be found in the following reference 

Riboldi-Tunnicliffe, A. & Hilgenfeld, R. (1999). Cryocrystallography with oil - 
an old idea revived J. Appl. Cryst. 32, 1003-1005 

Hope this helps

Alan

atunni@imb-jena.de
atunni@chem.gla.ac.uk