High-resolution DNA separation in microcapillary electrophoresis chips utilizing double-L injection techniques.

Area of Science:

• Microfluidics
• Biochemical Analysis
• Electrophoresis Technology

Background:

• Microfluidic chips offer platforms for high-throughput biochemical analysis.
• Effective sample injection is crucial for high-resolution separations in microchip electrophoresis.
• Sample leakage during injection can compromise separation efficiency and accuracy.

Purpose of the Study:

• To investigate high-resolution injection techniques for DNA fragment separation in electrophoresis microchips.
• To analyze the impact of electrokinetic migration, fluid flow, and diffusion on sample transport.
• To evaluate a novel double-L injection technique for reducing sample leakage.

Main Methods:

• Experimental and numerical simulations of microfluidic devices.
• Investigation of electroosmotic flow (EOF) using fluorescent dyes (rhodamine B and Cy3).
• Analysis of DNA fragment separation (100-bp DNA ladders, HaeIII-digested PhiX-174 DNA) using capillary electrophoresis (CE).

Main Results:

• The developed microfluidic chip's injection system successfully replicated conventional cross-channel and shift-channel injection functions.
• The double-L injection technique significantly reduced sample leakage in both EOF and CE separations.
• Experimental and simulation results confirmed the effectiveness of the proposed injection method.

Conclusions:

• The novel double-L injection technique effectively minimizes sample loss in microfluidic electrophoresis.
• This approach enhances the performance of microchips for high-resolution DNA fragment analysis.
• The developed microfluidic chip and injection method hold potential for high-throughput biochemical applications.