Most protein purification procedures require that all steps be done at refrigeration temperatures (4 °C). This is done partly to prevent the protein you're working on from accidentally denaturing as you remove it from the cellular environment. Ironically, there have been a couple of documented cases of proteins denaturing more easily at temperatures close to freezing (such as 4°C) than at room temperature. Explain how this could be.

A protein purification is a series of processes that allow the isolation of a single type of protein from a complex mixture. Protein purification is vital for the characterization of the function, structure interactions of the protein of interest, for example an enzyme a cell receptor or an antibody. The initial material is generally a biological tissue or a microbial culture. There are several steps in the purification process; it can release the protein from the matrix that confines it, separate the protein and non-protein parts of the mixture, and finally separate the desired protein from all the others. This last step may be the most laborious aspect of protein purification.

Techniques used

Homogenization

Cell fractionation

Reversible denaturation with ammonium sulfate

Chromatography

Electrophoresis

Dialysis

Ultraviolet-visible spectroscopy

Enzymatic assay