Size exclusion chromatography (SEC) is a liquid chromatographic technique in which particles are separated based on their size, or hydrodynamic volume. Particles of different size elute at different rates through the column, the larger eluting first. SEC is a particularly useful technique for large molecules, such as proteins and polymers. Since SEC measures hydrodynamic volume, rather than molecular weight, it may be used to assess the tertiary structure of a protein. SEC will differentiate between proteins with the same sequence/molecular weight, but with different molecular size due to variations in folding. This may be used as a comparative technique in batch release. It is a recommended technique in the ICH Q6B guidelines for assessment of molecular weight or size, and also for liquid chromatographic patterns.
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.
M-Scan in brief:
M-Scan has unrivalled expertise and experience as a problem-solving contract research laboratory. We are specialists in Mass Spectrometry, Chromatography and associated techniques for solving the most demanding problems in organic chemical analysis. We have a multi-disciplinary analytical team, specialising in the fields of biotechnology, pharmaceutical, industrial, environmental and forensic chemistry. We are at the cutting-edge of developing new and bespoke analytical techniques and have a large collection of validated proprietary methods. We are experts in the interpretation of analytical data.
M-Scan Brochure: Biotechnology and Pharmaceutical Analysis (8pp.)