why quick freeze-thaw cycles can improve protein recovery? - (Dec/04/2006 )
when preparing soluable cell extracts, some protocal recommend putting the lysate between liquid nitrogen and 37 water bath (freeze thaw cycles) to improve protein recovery , why is that ?
I think it's based upon principle about freezing makes water crystallize and increase its volume. I suppose freezing provokes cytoplasm disrupts plasma membrane, therefore it's a cell lysis method. Freeze-thaw repeatedly improves cell lysis, so improves protein recovery.
as soluble proteins are hydrated, slow freezing supports the building of more complex crystals which seem to do harm by, as a I propose, mechano-chemical processes
Freeze-thaw is a very gentle process, which is good for proteins, but it still gives good lysis of cells. Repeat cycles of freeze-thaw just gives better overall yield.
My guess as to the reason for going into 37 degree water (rather than just leaving them on the bench to thaw) is just to speed up the overall process, and to reduce the total amount of time the proteins are in a protease-friendly environment.