What is the primary function of ion exchange chromatography?

The primary function of ion exchange chromatography is to bind compounds based on their charge. In this technique, a column is filled with charged resin that can either be positively or negatively charged. When a mixture of proteins is passed through the column, proteins with an opposite charge to that of the resin will bind to it, while those with a similar charge will be repelled and eluted earlier. By altering the pH or ionic strength of the buffer, it is possible to elute the bound proteins in a controlled manner, allowing for their separation based solely on their charge properties.

This method is widely used in protein purification processes in biochemistry, particularly because proteins often carry various charges depending on their amino acid composition and the conditions of the environment (such as pH). The versatility to manipulate binding and elution conditions makes ion exchange chromatography a powerful tool for separating and purifying target proteins from a complex mixture.