Biochemical Techniques and Instrumentation

2.3.7.Technique

• The sample is applied on top of the column which contains the ion exchange resin.
• The molecules of interest get bound or adsorbed to the column.
• The column is washed with the equilibration buffer of low ionic strength.
• The impurities or unwanted ions that are not bound are eluted off using this buffer.
• The bound molecules are then eluted using a gradient buffer which steadily increases the ionic strength of the eluent.
• Alternatively, the pH of the eluent buffer can also be modified so as to give the molecule or the resin matrix a charge at which they will not interact.
• Finally, the molecule of interest is eluted from the resin.