A typical use of size exclusion chromatography (SEC) at SOLVE is as a high resolution quantitative method for monitoring degradation and oligomerization. Our SEC instrumentation is connected to MALS-RI detectors to enable direct and reliable molar mass determination, as an alternative to molar mass determination with standards. We have columns from different manufacturers to cover the size range from peptides to large polymers. We also use UV and FL detection.
Principle:
Size exclusion chromatography (SEC), also referred to as gel permeation or gel filtration chromatography (GPC/GFC), is a separation methodology that separates macromolecules in solution according to differences in size. The separation is based on the ability of the macromolecule to access the pores of the stationary phase. On-line detectors such as UV monitor the amount of the size separated components as they are eluted from the column.
Applicability:
Size exclusion chromatography (SEC) is applicable to a wide range of compounds, such as peptides, proteins, and polymers, with molecular weight of ~ 1000 g/mol up to ~10·106 g/mol. Typical uses are for stability testing of proteins, aggregation analysis, batch to batch control, molar mass distribution.
Pros
- High resolution
- Quantitative (with UV or RI)
- Especially well suited for <100 kDa compounds
- Suited for standardization
- Fractions can be collected
Cons
- Limited size range (poor >1 – 10 MDa)
- High surface area and shear rates
- Molar mass and Mw determination through standards unless coupled to MALS detector
- High salt buffer often required
- Concentration changes during separation