Ion exchange chromatography

Ion-exchange chromatography separates proteins according to their net charge. The stationary phase of the column will have a specific charge.

For example negatively charged proteins (anions) will bind to a positively charged diethylaminoethylcellulose (DEAE-cellulose) columns. The negative proteins bound to column can by eluted by adding a negatively charged buffer which will compete with the protein for binding to the column. Proteins that have lower charge density will be eluted first from the column .

The stationary phase is an insoluble matrix which will either carry a positve or negative charge. Whilst diethylaminoethylcellulose (DEAE-cellulose) is positively charged, an negatively charged matrix includes carboxymethylcellulose (CM-cellulose).