I have seen some conflicting advice on this point.
I always add 10% or 5% glycerol before flash freezing with liquid nitrogen. when i take out the protein from -80c freezer, i put it on ice or ice water to thaw slowly, it takes more than 30min, but today one of my lab member told me he always put the protein sample in room temperature water to thaw quickly, 5min is enough. so i feel a little bit confusing, whether fast thaw or slow thaw is correct to keep good enzymatic activity, or it depends on different protein? Any advice on this topic is appreciated. Thank you.
From my experience，it's always OK to thaw your protein on ice,and it only takes about 10 minutes,but at RT,yes,it depends on different proteins,I remember that one of my seniors,her protein will get turbid when she tries to thaw it at RT.Hope my experience will help you.
Depends on protein. It could change structure during "fast" defrost. I would stick with ice method like Zang Hang suggested.