A modification of this was done in pcr tubes, and it seemed to work even better:
Acta Cryst. (2004). D60, 203-204[ doi:10.1107/S0907444903024491 ]
An improved protocol for rapid freezing of protein samples for long-term storage
J. Deng, D. R. Davies, G. Wisedchaisri, M. Wu, W. G. J. Hol and C.
We routinely use a P200 to pipette drops of protein directly into a small Dewar
of liquid nitrogen. The protein forms small BB's with a volume of approximately
30 micro-L each. Pipette slowly, allowing the drops to freeze solid before
adding the next one. The frozen BB's can be picked up with fo
Hello Eric,
I would try not to store a protein for 3-4 days and set up drops as quickly as
possible. 3-4 days can be a long time for a sensitive protein. If you expressed
too much, add 15% glycerol and store the protein at -80deg. Gel-filtrate the
solution and re-concentrate before the next use.
Hello Eric,
Does your protein also precipitate at lower protein concentrations? In
isolated cases, we've had protein stocks precipitate overnight at 4 degrees,
and the only way around it was to store them diluted, and concentrate right
before any experiments/crystallization trials. In two cases,
Dear all,
I'm working on a protein which starts to precipitate after 3-4 days of storage
at 4 degrees or room temperature. The storage buffer contains 300 mM NaCl
because at lower salt concentrations it also tends to precipitate. Different
buffers and adding glycerol did not help although this
