Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Capillary Electrophoresis: Applications

Capillary Electrophoresis: Applications

Capillary electrophoretic separations offer various modes, each with unique applications. These modes include capillary zone electrophoresis, capillary gel electrophoresis, capillary array electrophoresis, capillary isoelectric focusing, capillary isotachophoresis, micellar electrokinetic chromatography, and capillary electrochromatography.
Capillary zone electrophoresis (CZE) separates ionic components based on their electrophoretic mobility. It has been used to separate proteins, amino acids,...

Electrophoresis: Overview

Electrophoresis: Overview

Electrophoresis is a powerful analytical separation technique that relies on the differential migration of charged species when subjected to an electric field. The core strength of electrophoresis lies in its ability to separate high-molecular-weight species in complex mixtures. It has found widespread use in biochemistry, molecular biology, and analytical chemistry, allowing the separation of compounds like amino acids, nucleotides, carbohydrates, and proteins with excellent resolution.
There...

Two-dimensional Gel Electrophoresis

Two-dimensional Gel Electrophoresis

Two-dimensional gel electrophoresis is a high-resolution protein separation method first introduced by O' Farrell and Klose in 1975. This method involves protein separation by two dimensions, mass and charge, making it more accurate than one-dimensional gel electrophoresis.
The first dimension separation uses the isoelectric focusing or IEF technique performed on immobilized pH gradient (IPG) strips that separate proteins according to their isoelectric points.
Biological samples, such as cells...

Capillary Electrophoresis: Instrumentation

Capillary Electrophoresis: Instrumentation

Capillary electrophoresis instrumentation typically consists of several key components. A high-voltage power supply generates the electric field necessary for the separation by connecting to an anode (the positively charged electrode) and a cathode (the negatively charged electrode) located in buffer reservoirs at each end of the capillary tube. The system includes a sample vial, a fused silica capillary tube coated with polyimide for mechanical strength through which the sample components...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity.

Proceedings of the National Academy of Sciences of the United States of America·2026

Same author

Establishment of a Single-Cell Minimal Medium: A Case Study for Microfluidic Cultivation of Corynebacterium glutamicum.

Biotechnology and bioengineering·2026

Same author

Accurate Sizing of Monodisperse Microbubble Suspensions by Optical Attenuation Spectroscopy.

Ultrasound in medicine & biology·2025

Same author

Cytokine-induced memory-like responses in endothelial cells link chronic inflammation to vascular disease risk.

Molecular omics·2025

Same author

A New Approach to Examine Cell-Antibody Avidity with Surface Plasmon Resonance Imaging.

Biosensors·2025

Same author

Electrolytic Bubble Coalescence on Hydrophobic Cavity Arrays Determines Departure Radius and Lowers Electrolyte Supersaturation.

Small (Weinheim an der Bergstrasse, Germany)·2025

Search research articles

Related Experiment Video

Updated: Jul 11, 2026

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method

Published on: September 19, 2018

Microfluidic high-resolution free-flow isoelectric focusing.

Dietrich Kohlheyer¹, Jan C T Eijkel, Stefan Schlautmann

¹MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands. d.kohlheyer@utwente.nl

Analytical Chemistry

|October 2, 2007

Summary

This study introduces an improved microfluidic free-flow isoelectric focusing chip for protein separation. The new device achieves higher resolution and peak capacity, enabling faster, more sensitive analyses for applications like clinical diagnostics.

More Related Videos

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids

Published on: March 2, 2012

Single Step Isolation of Extracellular Vesicles from Large-Volume Samples with a Bifurcated A4F Microfluidic Device

Single Step Isolation of Extracellular Vesicles from Large-Volume Samples with a Bifurcated A4F Microfluidic Device

Published on: February 2, 2024

Related Experiment Videos

Last Updated: Jul 11, 2026

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method

Highly Sensitive and Quantitative Detection of Proteins and Their Isoforms by Capillary Isoelectric Focusing Method

Published on: September 19, 2018

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids

On-chip Isotachophoresis for Separation of Ions and Purification of Nucleic Acids

Published on: March 2, 2012

Single Step Isolation of Extracellular Vesicles from Large-Volume Samples with a Bifurcated A4F Microfluidic Device

Single Step Isolation of Extracellular Vesicles from Large-Volume Samples with a Bifurcated A4F Microfluidic Device

Published on: February 2, 2024

Area of Science:

Analytical Chemistry
Biotechnology
Microfluidics

Background:

Traditional free-flow isoelectric focusing (FFE) lacks the resolution for complex biological samples.
Existing microfluidic FFE devices have limitations in separation efficiency and speed.
Protein analysis often requires high sensitivity and minimal sample volumes, unmet by current technologies.

Purpose of the Study:

To develop an enhanced microfluidic free-flow isoelectric focusing chip for improved protein separation.
To increase the resolution and peak capacity of microfluidic isoelectric focusing.
To demonstrate the device's capability for rapid and sensitive protein analysis.

Main Methods:

Development of a novel microfluidic FFE chip with multiple sheath flows and preseparated ampholytes.
Reduction of channel depth to enhance separation efficiency.
Demonstration of separation using fluorescent standards (pH 3-10) and human serum albumin (HSA).
Characterization of pH gradient stability and separation resolution with pI markers.

Main Results:

Achieved an almost linear pH gradient from 2.5 to 11.5 over 1.2-2 mm.
Successfully separated seven isoelectric focusing markers within 2.5 s at 20 V/mm.
Demonstrated separation of analytes with a minimum isoelectric point difference (ΔpI) of 0.4.
Reported an 8-fold increase in peak capacity (29 peaks/1.8 mm) compared to previous microfluidic FFE devices.
Observed analyte concentration increases of 20x or higher due to focusing.

Conclusions:

The improved microfluidic FFE chip offers significantly higher separation resolution and peak capacity.
The device is capable of rapid, sensitive protein separation, suitable for clinical analysis with low sample volumes.
Further optimization, including reducing electroosmotic flow, could enhance resolution even more.