Microfluidic enzymatic DNA extraction on a hybrid polyester-toner-PMMA device

Area of Science:

• Forensic Science
• Biotechnology
• Microfluidics

Background:

• Solid Phase Extraction (SPE) is the standard for DNA purification in forensic short tandem repeat (STR) polymerase chain reaction (PCR) analysis.
• SPE methods require PCR inhibitors and lengthy protocols (up to 30 min), hindering rapid analysis.
• EA1 protease enables enzymatic DNA extraction, simplifying template preparation but has not been integrated into microfluidic systems.

Purpose of the Study:

• To develop and evaluate a microfluidic device for rapid, enzyme-based DNA extraction.
• To integrate EA1 protease into a hybrid microdevice for efficient DNA extraction from buccal swabs.
• To demonstrate the suitability of the extracted DNA for forensic applications, specifically STR-PCR.

Main Methods:

• A hybrid microdevice was fabricated using laminated polyester (Pe) and polymethyl methacrylate (PMMA) layers.
• The PMMA layer served as a swab acceptor and macro-to-micro interface for sample introduction.
• DNA extraction was initiated centrifugally with pre-loaded reagents at 75 °C, with multiplexing capability demonstrated.

Main Results:

• DNA extraction was achieved in less than 3 minutes, eliminating the need for pneumatic pumping.
• The device yielded DNA concentrations up to 10 ng μL⁻¹ with a 100% success rate.
• Generated STR profiles confirmed the DNA's forensic quality, suitable for human identification.

Conclusions:

• The developed microfluidic device offers a rapid and simplified method for DNA extraction using EA1 protease.
• This technology significantly reduces processing time compared to traditional SPE methods.
• The microfluidic system provides high-quality DNA suitable for forensic analysis and human identification.