FAQ: How should I store my protein after it is purified?

Most proteins can be stored for at least a few days at 4°C without denaturing. For long term storage, one can either freeze at -70°C or dialyze into 50% glycerol and store at -20°C. When storing at -70°C, aliquot the protein so only the portion to be used must be thawed – repeated freeze/thaw cycles denature many proteins.