Ion exchange (IEX) is a crucial separation technique that is widely used in research laboratories and the biopharmaceutical industry. It is recommended for purification and polishing of many biomolecules, including antibodies, other proteins, nucleic acids and viruses, based on their net charge.
Sartobind® IEX membranes are available in a range of ready-to-use formats, to minimize set up time and ensure simple, flexible purifications.
Lab Scale IEX Chromatography Products
Sartobind® IEX Lab
Flexible, easy and ready-to-use IEX with any of the most popular chemistries.
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Vivapure® IEX
Rapid, economical IEX for parallel screening and small-scale purification.
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Top Considerations for Lab Scale Purification by IEX
Anion and cation exchangers should be used to capture molecules with a net negative or positive charge, respectively.
Ion Exchange Chemistries
Understanding the relationship between buffer pH and the net charge of your target biomolecule is important when choosing an IEX chemistry. When the buffer system that will be used for purification has been selected and the molecule pI is known, you'll find just how simple it is to choose between anion exchange (AEX) or cation exchange (CEX).
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Ion Exchange Buffers
Purification buffers for IEX should be chosen to ensure the stability of your target biomolecule. For a molecule that is only stable at a pH above or below its pI, this will also define the ligand to use (AEX or CEX, respectively). If stability is not important (e.g. your protein is denatured and will be refolded after purification) or the molecule is stable across a broad pH range either side of its pI, a buffer should be chosen according to you preference for AEX or CEX.
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IEX purification buffers should ensure biomolecule stability and suit the chosen membrane chromatography chemistry.
Ion Exchange Consumables
Quickly compare equipment compatibility, methods and reusability, to decide which lab chromatography consumable is right for your IEX purifications.
Sartobind® IEX Lab | Vivapure® IEX | |
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Syringe | ||
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Lab Filtration & Purification Resources
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Laboratory IEX Resources
Brochure
Lab Chromatography
Discover the full range of Sartorius lab chromatography consumables and kits.
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Datasheet
Sartobind® IEX Lab
Find the technical specifications and ordering information for pressure filter format IEX units.
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Datasheet
Vivapure® IEX
Refer to the technical specifications and ordering information for spin filter format IEX units.
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Frequently Asked Questions
Ion exchange membrane chromatography is a separation technique that uses ion exchange ligands to purify biomolecules based on small differences in net charge. It works in a similar way to column chromatography, but the ion exchange ligands are coupled to a stationary phase consisting of a macroporous membrane rather than microporous resins. This allows faster purification and higher yields of charged molecules such as antibodies, other proteins, peptides, nucleic acids, and viruses.
Sartobind® IEX Lab and Vivapure® IEX are both available with quaternary ammonium (Q) and diethylamine (D) anion exchangers or sulfonic acid (S) cation exchanger.
Ion exchange is broadly applicable to many target molecules. It can be used for capture purification or flow-through polishing of antibodies, other proteins, nucleic acids and viruses, based on their unique net charge. Ion exchange chromatography is also recommended for the removal of aggregates, host cell proteins (HCP) and DNA, as well as for virus and endotoxin clearance.
One, two or four units, a pair of Luer to UNF adapters and a quick start guide.
Eight or 24 units, 16 or 48 flowthrough and eluate collection tubes and a quick start guide.
Yes, they are. While we have taken steps to minimize our environmental impact with quick start guides in the product packaging, if you need more information on how to use our products, the full instruction manual can be downloaded from the relevant product page in our eShop.
Sartobind® IEX Lab can be used with or without equipment. A syringe or peristaltic pump can be connected directly to the Luer lock inlet for fast purification with minimal setup time. Alternatively, a pair of adapters are included for compatibility with most liquid chromatography systems.
Vivapure® IEX requires a benchtop centrifuge, pipettes and pipette tips.
The bed volume is also referred to as the membrane volume (MV). Several bed volumes are available to suit a range of screening and preparative purification applications:
- Vivapure® IEX Mini: 0.24 mL
- Vivapure® IEX Maxi: 2.7 mL
- Sartobind® IEX Lab: 0.41, 2.1 or 2.8 mL
These chromatography units are stable in most common purification buffers. Oxidizing agents should be avoided. For further information on pH compatibility, which varies by chemistry and exposure time, please refer to the instruction manuals.
Unlike with resin chromatography, there is no possibility of air bubbles disrupting Sartobind® membranes. This eliminates the need to degas buffers, saving considerable preparation time.
For optimal biomolecule capture, we recommend equilibration with a buffer similar in composition to the sample to be purified. This is a rapid process that adds only a few seconds to the purification cycle.
Although Sartobind® membranes are resistant to blocking, we recommend that all samples be pre-filtered before loading. To maximize productivity, a Minisart® syringe filter can be connected to the Sartobind® IEX Lab inlet for simultaneous prefiltration and sample loading.
Low-volume samples to be purified with Vivapure® IEX can be quickly pre-filtered with Vivaclear spin filters or Minisart® syringe filters.
A scouting purification should be performed to determine optimal capture and elution conditions. When purifying by centrifuge, syringe or pump, use a multi-step elution with buffers of gradually increasing ionic strength. If a liquid chromatography system is used, apply a linear elution gradient. An appropriate method (e.g. SDS PAGE) should then be used to analyze the flowthrough and eluent fractions and identify which conditions provide the required level of purity.
Purification methods should be optimized for each biomolecule, considering characteristics such as the buffer pH and conductivity, and the isoelectric point (pI) of the target. If the binding capacity is still insufficient after optimization, two to four Sartobind® IEX Lab units can be used in series. Alternatively, you can take advantage of the high flow rates by purifying a sample with multiple, smaller loadings over several cycles on a single unit.
While Vivapure® IEX is designed for single use, each Sartobind® IEX Lab unit can be reused many times. With proper regeneration and storage, the binding capacity can be maintained for at least 100 cycles.
We recommend using a separate Sartobind® IEX Lab unit for each target biomolecule to eliminate the risk of carryover.