Ion-exchange Chromatography Resins
Ion-exchange chromatography (IEX) is one of the most widely used chromatography techniques, which plays an important role in the separation and purification of biomolecules since the 1960s. IEC controls the reversible interaction between charged molecules and ion exchange media with opposite charges to achieve the binding and elution of specific molecules to achieve the separation effect. IEC widely uses in protein, skin, nucleic acids and other electric charges in the separation and purification of biomolecules. The advantages of high capacity and high resolution to well thousand among the whole process of capture, purification, and fine purification stage. IEC applies to the analysis of a small amount of sample, and the purification of sample preparation.
GALAK Ion-exchange Chromatography resins use agarose and monodisperse PS-DVB microspheres for substrates. For PS-DVB microspheres substrate, it has the advantages of high mechanical strength and excellent pressure resistance to meet the high requirements of preparative production conditions.
GALAK Technology Advantages
GALAK ion-exchange packing materials are a series of ion exchange media developed based on monodisperse PSDVB microspheres. Its matrix structure and hydrophilic polysaccharide base material, such as agarose, cellulose, is completely different. First of all, it has excellent mechanical properties, can withstand up to 10MPa pressure; Secondly, the large pore size of 1000A can guarantee the free entry and exit of biological macromolecules. Finally, the special coating technology of GALAK gives it enough hydrophilicity to ensure its excellent biocompatibility. The monodisperse particle size can effectively reduce the column pressure and mass transfer obstruction
GALAK ion-exchange packing materials use "tentacles" surface derived technology, functional groups in the form of linear polymer chain covalently combined on the surface of the substrate. Relative to the traditional ion exchange medium directly on the surface modification or with only short-chain in combination with the pattern of functional groups, GALAK ion-exchange packing materials has more effective number of functional groups, not only its space steric hindrance to reduce macromolecular protein, antibody, viruses, and plasmid can more effectively combine with medium of functional groups, significantly increase capacity, and "tentacles" structure can effectively reduce enough biological molecules and nonspecific interaction between the dielectric substrate, so as to improve the recovery rate of target molecules.
Selection Of Ion-exchange Packing Materials
In practical applications, the substrate type, pore structure, particle size and distribution, substrate type and density of ion-exchange media will affect the tomographic effect of the medium.
- The porosity of the substrate provides a large surface area covered with charged groups, thus ensuring a high bonding capacity. However, the large pore size ensures the effective mass transfer of protein biomolecules.
- The hydrophilic substrate has better biocompatibility and less non-specific adsorption.
- The high chemical stability ensures that the medium can be cleaned with a vigorous cleaning solution if necessary.
- The high physical stability ensures that the volume of the column bed remains constant when the concentration of salt ions or the pH value changes dramatically. This can increase the repeatability of the system, less unnecessary reloading column. At the same time, the consistency of particle size distribution is beneficial to the operation of high-speed liquid flow, especially in cleaning or rebalancing steps, which can increase the flux and working capacity of the system.
|Sulfonic Group S/SP||Strong Type||-SO32-|
|Carboxymethyl CM||Week Type||-COO|
|Quaternary Ammonium Q||Strong Type||-N+(CH3)3|
|Tertiary Amine D||Week Type||-N+H(CH3)2|
Strong ion-exchange media have the following advantages
- Since the charged nature of the medium does not change with the change of pH, the establishment and optimization of the separation process will be very fast and easy.
- Since there is no intermediate form of charge interaction, the interaction mechanism is simple.
- At high or low pH, the binding capacity of the sample is maintained because the ion-exchange medium does not lose charge.
Most proteins have isoelectric points between 5.5 and 7.5 and can be separated by a strong or weak ion-exchange medium. The advantage of weak ion-exchange media, such as D and CM, is that they offer different selectivity than strong ion-exchange media. The disadvantage is that weak ion-exchange media gain or loses protons as pH changes, so their ion-exchange capacity changes as pH changes.
When the desired selectivity cannot be obtained with strong ion-exchange media (Q, S, SP), weak ion-exchange media such as D, CM can be tried. When using a weak ion exchanger, use a float that minimizes the effect in the following pH range:
- D: pH 2-9
- CM: pH 6-10