Size exclusion, also known as gel filtration, chromatography separates proteins based on their sizes (hydrodynamic radii) in solution and not by absolute molecular weight with larger sized species eluting before smaller peptides. The primary driving mechanism for this isocratic based technique is based on the pore size and volume of the SEC particles used in the packed column. SEC columns containing comparatively larger pore size particles are selected as the molecular weight of the peptides of interest increase.
As with other bioseparations, use smaller particle size, UPLC/UHPLC offerings provide superior component resolution and in less time compared to our HPLC-based columns for this demanding application.
BioSuite Size Exclusion Columns
The molecular weight exclusion limits of BioSuite SEC packings are determined primarily by the selected pore size of the silica-based material used in the column offering. In addition, the particle size of the SEC packing media as well as the column length are important parameters that determine separation efficiency. Ranked by separation efficiency, BioSuite UHR columns (calibration table not shown) provide the highest level, followed by BioSuite HR, and Standard SEC columns.
Protein-Pak Size-Exclusion Chromatography (SEC) Columns
Protein-Pak packings are based on a 10 μm diol-bonded silica and are available in a variety of pore sizes and column configurations. The Protein-Pak SEC Columns:
The degree of resolution is more dependent on the sample mass and volume than the interaction between the sample and the stationary phase. Ideally, there should be no interaction between the stationary phase and the sample molecules. Potential interactions are reduced by adding salts in the 0.1–0.3 M concentration range.