Dear all,

Recently, I got a crystallization condition as 0.1 M Bis tris ph 6.5,
1.3Mlithium sulfate,
0.1M NaCl, the shape of crystals is needle cluster, very difficult to grow
bigger, microseeding does not work, then I tried macroseeding, and found
crystal can grow bigger and rod like. However as for the cryoprotectant,
crystal will dissolve in glycerol, ethylene glycol, MPD and PEG, even in the
very low concentration about 5%. I found my crystal can grow under the
additive 2-propanol in addition to the above mentioned crystallization
condition. I also noticed that Hampton cryoprotectant kit has the 2-propanol
as cryoprotectant. I want to know if anyone have ever used 2-propanol as the
cryoprotectant and what effect it might be. By the way Hampton also mention
lithium sulfate can be used as cryoprotectant, the recommended maxium
concentration is 2M, I tried and found ice ring is severe and it is very
easily to form lithium sulfate salt crystal at this high concentration,  I
also tried sodium malonate, the diffraction gave me few spots, resolution is
only about 6--7 angstrom.

Does anyone encounter such problem by lithium sulfate?


Welcome to any replies. Thanks a lot in advance.

Donghui

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