Capillary Isoelectric Focusing
Capillary Isoelectric Focusing - Related Videos
07:58
Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method
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2018
Capillary isoelectric focusing is an antibody-based, ultrasensitive, high throughput technique, enabling detailed characterization of proteins and their isoforms from extremely small biological samples. The following describes a protocol for detection and quantification of specific proteins and their isoforms in an automated and robotized manner.
03:11
Liquid Phase Isoelectric Focusing: An Electrophoresis Technique to Separate Bioactive Molecules from Crude Gymnema sylvestre Extract
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2025
This video describes a technique to separate complex molecules from plant extracts using liquid phase isoelectric focusing. This technique helps purify complex biomolecules in their native state which can be used for various downstream applications.
09:57
Separation of Bioactive Small Molecules, Peptides from Natural Sources and Proteins from Microbes by Preparative Isoelectric Focusing (IEF) Method
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Cited by 4 •
2020
The objective is to fractionate and isolate bioactive small molecules, peptides from a complex plant extract, and proteins from pathogenic microbes by employing liquid-phase isoelectric focusing (IEF) method. Further, the separated molecules were identified and their bioactivity confirmed.
08:50
Capillary Electrophoresis (CE)
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2023
Source: Laboratory of Dr. B. Jill Venton - University of Virginia Capillary electrophoresis (CE) is a separation technique that separates molecules in an electric field according to size and charge. CE is performed in a small glass tube called a capillary that is filled with an electrolyte solution. Analytes are separated due to differences in electrophoretic mobility, which varies with charge, solvent viscosity, and size. Traditional electrophoresis in gels is limited in the amount of voltage...
14:53
Capillary Electrophoresis Separation of Monoclonal Antibody Isoforms Using a Neutral Capillary
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Cited by 2 •
2017
Here, we present a comprehensive capillary zone electrophoresis protocol for the assessment of intrinsic physicochemical heterogeneity of monoclonal antibodies as a quality attribute.
FAQs
Carrier ampholytes create a continuous pH gradient inside the capillary when an electric field is applied. Because each amphoteric molecule responds to the local pH, molecules with different isoelectric points move to different positions along that gradient. The resulting spatial separation reflects differences in molecular charge behavior rather than simply differences in molecular size.
A protein moves through the gradient until it reaches the pH corresponding to its isoelectric point, where its net charge is zero. At that location, the focusing process concentrates the protein into a narrow zone. This concentration improves resolution and helps distinguish closely related protein species during chemical characterization.
Charge heterogeneity appears when related protein species focus at different positions because they have different isoelectric points. These differences can indicate variation in the chemical composition or structural state of the sample, without requiring separation based on molecular size. Examining the pattern of focused zones therefore supports assessment of sample complexity and composition.
The method separates molecules according to their isoelectric points, the conditions at which their net charge becomes zero, within an established pH gradient. This differs from a simple separation based only on whether molecules carry positive or negative charge. Its focusing behavior produces localized zones, supporting high-resolution comparison of proteins with similar overall characteristics.
The essential workflow places the amphoteric sample in a narrow capillary containing carrier ampholytes, applies an electric field, and allows the ampholytes to establish a stable pH gradient. Sample molecules then migrate through that gradient and focus at their respective isoelectric positions. The resulting zones can be examined for identification, purity, or charge variation.
It is useful when researchers need to identify proteins, evaluate sample purity, or examine charge heterogeneity in a complex mixture. Because separation occurs with small sample requirements and efficient focusing, the method suits chemical analysis, biochemistry, pharmaceutical analysis, and investigations of biomolecular structure and composition.
The positions of focused zones provide information about the isoelectric behavior of molecules in the sample, while the number and distribution of zones can reveal whether multiple charge forms are present. This pattern helps researchers characterize composition and assess purity, particularly when a sample contains related proteins that differ in charge properties.
The technique connects measurable electrophoretic behavior with molecular charge and composition. In chemistry-focused research, that relationship supports characterization of amphoteric molecules, especially proteins, by resolving differences in isoelectric points. Its high resolution, low sample requirement, and efficient separation make it valuable for studying complex biomolecular samples and evaluating their chemical consistency.