Size Exclusion Chromatography with Multi Angle Light Scattering (SEC-MALS)

​Application: Protein characterisation (molecular mass, oligomerisation, complexes)

​Instrument: OmniSEC (Malvern)

​Location: VBC6, room 103

SEC-MALS is used to measure the weight-averaged molar mass of proteins (and other macromolecules) in solution, and can determine oligomeric state and sample polydispersity. Size-exclusion chromatography (SEC) separates molecules based on hydrodynamic volume, but is dependent on similarity to a set of reference standards for accurate mass determination and fails for elongated or sticky proteins. Multi-Angle Light static Scattering (MALS) is used to measure light scattering intensity accurately, which is proportional to the weight-averaged mass in solution. Combining SEC, MALS and concentration detectors in a SEC-MALS experiment allows for more accurate mass measurements that SEC or MALS alone.

By using two concentration detectors (RI and UV), the molar mass and weight-fraction of a biomolecular heterocomplex can be determined. This can be used to measure protein and modifier masses of integral membrane proteins in detergent micelles and of glycosylated proteins.  

Sample requirements: 100 μg/injection (e.g. 50 μL at 2 mg/mL)

Measurements are exclusively performed by ProTech staff upon request.
Data analysis training by ProTech staff is possible upon request.