Purification of proteins at 4 degrees

Yes you can put the FPLC in a refrigerator at 4 C without any adverse effects. We have probably ~10 in refrigerators where I work. The only caveat is that when you place it in that environment you must allow the instrument to equilibriate to the temperature before running it and the same goes if you move it any where with a significant difference in temperature otherwise you may lose protein due to the components being slightly out of tolerance. I do not recommend putting the computer in the refrigerator / cold room with the instrument due to the possibility of condensation.

Dear Chris L, thank you for your suggestions. Alternately, instead of putting the whole AKTA purifier set up inside refrigerator, I was thinking to use chilled buffer(putting buffer solution in ice) during equilibration and purification of my protein. Will it have the same effect on the entire purification process ?

Possibly...I have no experience doing it like that. The one thing I can think of is if you use a SuperDex that is warm and run 4 C solution through it you will probably break it due to the temperature difference.