Protein Purification

Protein purification is the process of extraction of proteins while excluding cellular components and other contaminants. The purification processes may involve several different principles such as differences in protein size, physicochemical properties, binding affinity and biological activity. Initially, the extraction process may be carried out by repeated freezing and thawing, homogenization by high pressure, lysis using detergents or enzymes, or other techniques. Following this, the cell debris is separated from the proteins and other soluble cell components by centrifugation.

There are several different purification processes and techniques available to work with proteins. Initial steps include precipitation using agents such as ammonium sulphate, using detergents to dissolve cell membrane proteins. For the actual purification, there are several chromatographic techniques available such as size exclusion, ion-exchange, affinity chromatography, HPLC and so forth.

There are various chemical reagents required for purification procedures which are conveniently bundled in kits etc. On Biomall, these are available from popular brands that include Pierce, BD Biosciences, HiMedia and several more.