Ion Exchange Chromatography (IEX / IEC)

Ion Exchange Chromatography (IEX / IEC) - in this technique proteins including antibodies, small nucleotides and amino acids may be separated depending on their net charge. Either cation or anion exchange chromatography may be employed, retaining positively-charged or negatively charged analyte ions, respectively. Since proteins have numerous functional groups containing positive and/or negative charges, ion exchange chromatography is a useful method for purification and separation of proteins. It is one of the recommended techniques for liquid chromatographic patterns in the ICH Q6B guidelines.