Chip Capillary Electrophoresis

Introduction of Chip Capillary Electrophoresis

Capillary electrophoresis is a popular analytical technique that allows the separation of molecules based on their electrophoretic mobility with the use of an applied voltage in a capillary tube containing polymer/gel mediums. The electrophoretic mobility is dependent on the charge of the molecule, the viscosity, and the atom's radius. Capillary electrophoresis can be coupled online with MS to be applied for analysis of proteins and peptides. In the early 1990s, chip-based capillary electrophoresis was designed and developed based on the principle of capillary electrophoresis. Microchip capillary electrophoresis can be integrated with various miniaturized functional elements to realizing mixture, reaction, concentration, and separation of analytes on a chip, greatly decreasing injection volumes, reducing separation lengths, resulting in a reduction of analysis time. As a new and powerful analytical technology, microchip capillary electrophoresis is also applied for high-speed separation of biological compounds such as DNA and proteins.

Fig. 1 Capillary electrophoresis microchip.^1,3

Compared to traditional capillary electrophoresis, chip-based capillary electrophoresis has several advantages, including

• Enhancing separation resolution of different samples
• Requiring lower consumption for sample and reagents
• Faster and more miniaturized analysis
• High throughput and multiplexed assays
• More easily automated
• Integration capability

Materials of Capillary Electrophoresis Microchips

• Glass

Being a silicon compound, glass is an important substrate material in the construction of microchip capillary electrophoresis systems, with the advantages of excellent optical properties, well-developed microfabrication, and the same surface chemistry as the fused silica capillaries used for conventional capillary electrophoresis. However, there are also disadvantages such as complicated processing, high manufacturing cost, and fragility. In view of these disadvantages, polymer substrates for the fabrication of microchips have attracted a significant amount of attention.

• Polymer

Polymer substrates are cheaper and easier to manufacture than glass. The polymer is manufactured through the use of direct-write protocols using electron beams, ultraviolet lasers, or X-rays or through a molding process. Either manufacturing method can provide high-throughput and use lower-cost materials. The main limitation of the polymers used for capillary electrophoresis microchips is that the surface chemistry of these materials is poorly understood and poorly controlled.

Microchips Operation

Injection, separation, and detection is a standard analysis protocol for microchip capillary electrophoresis.

Application of Capillary Electrophoresis Microchips

• DNA Separation

Microchip capillary electrophoresis technique has been applied for DNA separation for sequencing and fragment analysis. The operation method is very similar to traditional capillary gel electrophoresis.

• Protein Analysis

Microchip capillary electrophoresis can be also applied for protein analysis, involving separation of fluorescently labeled proteins, characterization of proteins, and measuring the purity of protein samples. Especially microchip-based capillary electrophoretic immunoassays allow direct measurement of protein analytes from complex samples such as blood and urine, making them become very useful tools for clinical application.

Services at Creative Biolabs

Creative Biolabs is an excellent and world-leading service provider who is devoted to helping our clients to design and develop top-quality microfluidic chips. Equipped with state-of-the-art development facilities and comprehensive expertise, we support a widely full range of microfluidic chip development services. We have accumulated extensive experience in several important projects of microfluidic-based development. Please contact us to let us help you design and develop the best effective microfluidic chip technologies.

Published Data

The following are results highlighted in articles related to the microfluidic-based capillary electrophoresis.

1. Microfluidic capillary electrophoresis chip for detection of ciprofloxacin in milk

Fig. 3 Schematic of the microfluidic capillary electrophoresis chip and the test result.^2,3

Detecting antibiotics in the milk supply chain is crucial for protecting humans from allergic reactions and preventing the development of antibiotic resistance. This study introduces the microchip capillary electrophoresis dairy device, an affordable system that employs microchip capillary electrophoresis and fluorescence spectroscopy to identify ciprofloxacin in milk. The device has demonstrated the ability to distinguish between milk samples without ciprofloxacin and those that contain the antibiotic, showing a linear correlation between ciprofloxacin concentration and output voltage. The detection limit for ciprofloxacin using this device was determined to be 0.19 mM, with a sensitivity of 10.5 mV/mM.

References

1. Chang, Leong, et al. " Experimental and Numerical Analysis of High-Resolution Injection Technique for Capillary Electrophoresis Microchip." International Journal of Molecular Sciences 12.6 (2011): 3594-3605.
2. Bosma, Rick, et al. "Microchip capillary electrophoresis dairy device using fluorescence spectroscopy for detection of ciprofloxacin in milk samples." Scientific Reports 10.1 (2020): 13548.
3. Distributed under Open Access license CC BY 4.0, without modification.