Urea and protein storage - (Mar/15/2009 )

Can someone please tell me whether storage of a protein (inclusion bodies of a recombinant protein containing Cys, protein concentration >10mg/mL) in 8M urea at minus 80oC would result in some chemical changes? Thanks

i store my purified protein in 8M urea at 4 degrees for ages and it seems fine, if that helps

Hey

I don't know about long term storage but for a short duration, just leave it at room temperature....Urea will precipitate even at 4 degrees so -80 is surely not recommended according to me.....However I never stop at this stage.

Best
TC

I'm so impressed with your super fast answers.
This helps to reassure me somehow. Great thanks.

a problem could arise when you defrost the solution. urea does not like temperatures above rt.

if you defrost at higher temperature (to speed it up) then you run the risk of carbamylating your protein.

mdfenko on Mar 17 2009, 02:39 AM said:

Dear mdfenko. You are just terrific!
When at rush I'd thaw samples by holding/rubbing in palm instead of using an waterbath. How much carbamylating could this generate? Anyway, I will wait on ice from now.
Do you know if carbamyls are known for affecting the antigen-antibody binding? Thanks a lot!

bachai on Mar 16 2009, 11:23 PM said:

it depends on the specificity of the antibody.