Sample introduction interface for on-chip nucleic acid-based analysis of Helicobacter pylori from stool samples.

Area of Science:

• Biomedical Engineering
• Microfluidics
• Diagnostic Systems

Background:

• Microfluidic diagnostic systems often neglect sample introduction, particularly for large volumes.
• Direct processing of crude samples like stool remains a challenge for integrated diagnostics.

Purpose of the Study:

• To develop a microfluidic sample introduction interface for direct, on-chip processing of crude stool samples.
• To enable rapid DNA extraction of Helicobacter pylori (H. pylori) for point-of-care applications.

Main Methods:

• Adapted the immiscible filtration assisted by surface tension (IFAST) principle with a large volume sample chamber and septum interface.
• Integrated on-chip storage and reconstitution of chaotropic salt and superparamagnetic particles (PMPs) for DNA release and binding.
• Utilized magnetic separation through washing and elution chambers for purified DNA in aqueous media.

Main Results:

• Demonstrated direct on-chip processing of crude stool samples for H. pylori DNA detection.
• Achieved a complete DNA extraction process in just 7 minutes.
• Enabled a 40-fold reduction in working volume from crude biological samples.

Conclusions:

• The developed interface allows for rapid, simplified DNA extraction from crude stool samples.
• The system integrates a real-world sample interface with efficient DNA purification.
• This methodology shows significant potential for development into point-of-care (POC) diagnostic devices.