1. How do I know which size exclusion resin to use for my protein?
Select a resin where the target protein is located in the middle of the separating range. This will allow larger molecular weight as well as lower molecular weight to be well resolved from the target. Please consult the TOYOPEARL HW resin that best meets this.
2. Why is Size Exclusion Chromatography not used in large scale processes?
Size Exclusion Chromatography is a non-adsorptive mode. This means that there is no calculated binding capacity and the amount charged to an SEC column is dependent on the column size, the concentration of the injection, the volume of the injection and the operating flow rate. Typically the size of the column used when scaling up a process requires signicant increases in column size and height which are not economically feasible.
3. Since Size Exclusion is not used in large scale process what alternatives are available?
Tosoh Bioscience often recommends using HIC as an attractive alternative to SEC. Although HIC does not have the binding capacity of IEC, it is quite powerful at separating isoforms of the protein (such as aggregates and misfolded species) that may not be resolvable on ion exchange resins.
4. How fast can I run an SEC column? If I run at a lower flow rate, do I get better resolution?
TOYOPEARL SEC resins are rated to withstand up to 3 bar. However, running at lower flow rates maximizes sample exposure to pore volume allowing for better resolution between molecules.