Integrated printed circuit board device for cell lysis and nucleic acid extraction

Area of Science:

• Biomedical Engineering
• Microfluidics
• Molecular Diagnostics

Background:

• Sample preparation is a critical bottleneck in microfluidic diagnostic devices.
• Current methods for nucleic acid extraction from biological samples are often complex and time-consuming.
• There is a need for integrated, automated sample preparation solutions for point-of-care diagnostics.

Purpose of the Study:

• To develop and validate a novel microfluidic device for the direct preparation of nucleic acids from raw biological samples.
• To integrate printed circuit board (PCB) technology with isotachophoresis (ITP) for efficient sample processing.
• To demonstrate the device's capability in extracting pathogenic nucleic acids from whole blood.

Main Methods:

• A microfluidic device was fabricated with integrated resistive heaters, temperature sensors, and a microchannel.
• Whole blood samples spiked with Plasmodium falciparum were directly introduced into the device.
• On-chip lysis and mixing were achieved using integrated heaters, followed by nucleic acid extraction via isotachophoresis.
• Micro-particle image velocimetry (micro-PIV) was used to analyze fluid dynamics, and quantitative polymerase chain reaction (qPCR) was used for nucleic acid quantification.

Main Results:

• The device successfully lysed and mixed whole blood samples, enabling nucleic acid extraction.
• Isotachophoresis effectively purified and concentrated nucleic acids from the processed samples.
• A clinically relevant limit of detection of 500 parasites per microliter was achieved for Plasmodium falciparum.
• The system demonstrated high efficiency with minimal sample volume (1 μL).

Conclusions:

• The developed microfluidic device offers a robust and integrated solution for raw biological sample preparation.
• The combination of PCB technology and isotachophoresis provides an efficient platform for nucleic acid extraction.
• This technology has the potential for broad application in molecular diagnostics, particularly for infectious disease detection.