DNA separation with low-viscosity sieving matrix on microfabricated polycarbonate microfluidic chips

Area of Science:

• Materials Science
• Biotechnology
• Analytical Chemistry

Background:

• Microfluidic devices offer miniaturized platforms for various applications.
• Polycarbonate (PC) is a suitable substrate material for microfluidic chip fabrication.
• Improving the durability and reproducibility of microfluidic chip fabrication is crucial for widespread adoption.

Purpose of the Study:

• To develop a robust hot embossing method for fabricating polycarbonate microfluidic devices.
• To enhance the longevity of silicon master templates used in hot embossing.
• To demonstrate the performance of fabricated devices for capillary electrophoresis (CE) separation of DNA fragments.

Main Methods:

• Fabrication of microfluidic devices on polycarbonate substrates using hot embossing with silicon master templates.
• Incorporation of auxiliary lines on the silicon master to improve mold durability and bonding strength.
• Capillary electrophoresis (CE) separation of Phi X-174/HaeIII DNA restriction fragments using a low-viscosity sieving matrix (HPMC-50).

Main Results:

• Achieved high-resolution and reproducible CE separation of DNA fragments on fabricated PC microfluidic chips.
• Demonstrated significantly improved bonding strength between the PC substrate and cover plate.
• Extended the lifetime of the silicon master mold, enabling over 300 replications.
• Identified temperature as a critical factor influencing separation efficiency.

Conclusions:

• Hot embossing is an effective method for fabricating durable and reproducible polycarbonate microfluidic devices.
• Auxiliary lines on master templates enhance mold life and chip bonding.
• The developed microfluidic devices are suitable for high-performance DNA separation via CE.