Suresh Kumar Kailasa - Miniaturized Analytical Devices: Materials and Technology

1. Chapter 2
2. Chapter 3
3. Chapter 4
4. Chapter 7
5. Chapter 9
6. Chapter 10
7. Chapter 12
8. Chapter 13

1. Chapter 1
2. Chapter 2
3. Chapter 3
4. Chapter 4
5. Chapter 5
6. Chapter 6
7. Chapter 7
8. Chapter 8
9. Chapter 9
10. Chapter 10
11. Chapter 11
12. Chapter 12
13. Chapter 13

Edited by Suresh Kumar Kailasa and Chaudhery Mustansar Hussain

Suresh K. Kailasa

Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat-395007, Gujarat, India

ASPEE Shakilam Biotechnology Institute, Navsari Agricultural University, Surat-395007, Gujarat, India

Department of Chemistry, National Institute of Technology Srinagar, Hazratbal Kashmir 190006, Kashmir, India

Microchip capillary electrophoresis ( MCE ) is one of the efficient bioanalytical tools for rapid separation and detection of bioactive molecules with high separation resolution [.

In this chapter, we summarize the recent developments of MCE for separation and identification of nucleic acids and proteins from clinical and food samples. We briefly describe the history and role of MCE in clinical and food microbial research. A section is devoted to applications of MCE for separation and identification of nucleic acids, proteins, and biomarkers from clinical and food samples. The analytical features of MCE for rapid separation and detection of biomolecules are tabulated, which provides significant information to scientists to know potential advancements of MCE in molecular biology.

Generally, MCE consists of four core parts: microfluidic chip, electric field, separation, and detector. The electric field is applied for sample concentration and separation. displays a T-shaped microfluidic chip. The microfluidic chip contains few reservoirs such as sample and buffer reservoirs. These reservoirs should be filled with a background solution, and sieving gels and pipetting and syringe pumps are used for fluidic control. Once the microfluidic chip is set up with these parts, a high electric field is applied to the reservoirs (sample) to separate the target analytes. The detector is placed at the end of the separation channel, which results in registering the zones for separation and transmitting the data for signal processing unit, which generates an electropherogram. In this section, an overview of fabrication of microfluidic chips, sample preparation (on-microfluidic chip), separation, and analyte detection is given.

So far, several methods have been adopted for the fabrication of microfluidic chips, such as reactive ion etching, wet etching, photolithography, conventional machining, hot embossing, injection molding, soft lithography, in situ construction, laser ablation, and plasma etching [11, 12]. Silicon or glass is used as raw materials for the fabrication of microfluidic chips. Microfluidic electrophoresis chips consist of two reservoirs (sample and buffer) connected to the separation channel. A wide variety of materials including ceramics, glass, and polymers (poly(methyl methacrylate), cyclic olefin copolymers, polycarbonate, polystyrene, and fluorescent poly(p-xylylene) polymer (Parylene-C) have been used for preparation of microfluidic chips. Paper and fabric-based disposal chips have also received attention in MCE . Electroosmotic flow (EOF) is generated in microfluidic chips as the reservoirs are filled with a background solution or electrolyte. Since EOF significantly obstructs separation, microfluidic chips are coated with various chemicals and hydrogels to suppress EOF.

with permission.

Crossed-channel and T-shaped microfluidic chips are widely used in MCE, and the microchip channel is connected perpendicularly to other channels (sample and buffer). Microfluidic chips are also prepared with different designs. For example, a microfluidic chip (Agilent Bioanalyzer chip) is prepared with 16 reservoirs, of which 12 are for sample reservoirs and four for references and reagents. Accordingly, MCE has been successfully applied for the analysis of various bioactive molecules with high precision and accuracy. Microfluidic chip channels with a width of 10100m and a depth of 1540m are considered the best design for separation of analytes. Also, separation channel area is designed to be 165mm and 88 mm2 and the number of channels of microchips is increased to 12384 for separation of nucleic acids and multiple genotyping (384) molecules with reduced time and increased accuracy . Furthermore, microchips are designed with 8, 12, 16, 48, and 384 parallel channels for rapid and efficient separation of a wide variety of analytes.

The electric field (voltage application) and hydrodynamic pressure are applied for sample injection in MCE. On-chip peristaltic pump is used for hydrodynamic injection . Further, hydrodynamic injection system requires a pump or pipette, which limits its use in MCE. It is usually carried out by variations in pressure, vacuum, reservoir (sample waste), and fluid levels of sample.