Ion Exchange Chromatography
Ion Exchange Chromatography - Related Videos
08:52
Ion-Exchange Chromatography
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2023
Source: Laboratory of Dr. B. Jill Venton - University of Virginia Ion-exchange chromatography is a type of chromatography that separates analytes based on charge. A column is used that is filled with a charged stationary phase on a solid support, called an ion-exchange resin. Strong cation-exchange chromatography preferentially separates out cations by using a negatively-charged resin while strong anion-exchange chromatography preferentially selects out anions by using a positively-charged...
01:09
Ion-Exchange Chromatography
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2024
Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...
03:28
Selective Purification of a Bacterial Protein by Negative Ion-Exchange Chromatography
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2025
Source: Kuo, T., et al. One-step Negative Chromatographic Purification of Helicobacter pylori Neutrophil-activating Protein Overexpressed in Escherichia coli in Batch Mode. J. Vis. Exp. (2016)The video demonstrates a negative chromatography technique to purify a virulence-associated protein from a bacterial lysate. By using a positively charged resin in a buffered solution, host-cell proteins are selectively retained, while the near-neutral target protein remains unbound and is collected in the...
11:09
Online Size-exclusion and Ion-exchange Chromatography on a SAXS Beamline
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Cited by 40 •
2017
The determination of the solution structure of a protein by small angle X-ray scattering (SAXS) requires monodisperse samples. Here, we present two possibilities to ensure minimal delays between sample preparation and data acquisition: online size-exclusion chromatography (SEC) and online ion-exchange chromatography (IEC).
01:17
Ion Exchange
0 Views •
2024
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...
FAQs
Changing the mobile-phase pH modifies the electrical interactions between the charged stationary phase and molecules in the sample. As those interactions change, some biomolecules may remain associated with the column while others elute at different times. This makes pH adjustment useful for controlling retention and improving the resolution of proteins, peptides, nucleic acids, and other charged biological compounds.
Ionic strength is another mobile-phase condition that changes how strongly charged molecules interact with the stationary phase. Adjusting it can alter molecular retention and promote elution at different points in the separation. Because biological samples contain compounds with varied charge properties, controlling ionic strength helps separate components according to their electrical interactions rather than treating the sample as a single mixture.
The method distinguishes components because biomolecules can differ in net electrical charge and therefore interact differently with the charged stationary phase. Those differences produce different retention behaviors as the mobile phase conditions change. The resulting separation allows individual proteins, peptides, nucleic acids, or other charged compounds to be analyzed or collected more selectively from a complex biological mixture.
A biological sample is passed through a column containing the charged stationary phase. Molecules with interactions that favor binding are retained, while the separation is controlled by modifying the mobile phase. Changing its pH or ionic strength alters those interactions and causes components to elute at different times. The collected fractions can then support analysis or purification of selected biomolecules.
Researchers may select this technique when they need to analyze or purify charged biological compounds, including proteins, peptides, nucleic acids, and related biomolecules. Its ability to separate components according to net electrical charge makes it relevant to protein characterization and enzyme studies. It can also prepare a more suitable sample for later biochemical or structural analyses.
Ion exchange chromatography can reveal how components in a biological sample differ in charge-dependent retention and can help isolate compounds for further study. In biology, those outcomes support protein characterization, enzyme investigations, and preparation of purified material for downstream biochemical or structural analyses. The technique therefore serves both as an analytical separation method and as a purification step.