Low cost and manufacturable complete microTAS for detecting bacteria

Area of Science:

• Biomedical Engineering
• Microfluidics
• Molecular Diagnostics

Background:

• Traditional bacterial detection methods are often time-consuming and require complex laboratory setups.
• There is a need for rapid, low-cost, and integrated systems for bacterial detection in various sample types.
• Lab-on-a-chip (LOC) technology offers a promising platform for miniaturized and automated diagnostic assays.

Purpose of the Study:

• To develop and demonstrate a fully integrated lab-on-a-chip system for automated bacterial detection.
• To design a low-cost, disposable plastic chip amenable to mass production via injection molding.
• To integrate multiple steps including bacterial lysis, nucleic acid isolation, polymerase chain reaction (PCR), and fluorescent detection onto a single chip.

Main Methods:

• A novel porous polymer monolith (PPM) embedded with silica was utilized for bacterial lysis and nucleic acid isolation.
• The disposable chip was fabricated from Zeonex, a thermoplastic chosen for its high melting temperature, UV transmissibility, and low auto-fluorescence.
• A prototype instrument was developed to automate fluid control (using remote valve switching and speed-changing reservoirs), thermal cycling, and optical detection.

Main Results:

• The integrated LOC system successfully performed bacterial lysis, nucleic acid isolation, and PCR amplification.
• End-point fluorescent detection was achieved using a Taqman assay on-chip.
• The system demonstrated functionality using Bacillus subtilis as a model bacterial target, confirming successful bacterial DNA detection.

Conclusions:

• The developed integrated lab-on-a-chip system provides a fully automated and low-cost solution for bacterial detection.
• The use of a novel PPM and a valveless chip design facilitates efficient sample processing and low-cost manufacturing.
• This technology has the potential to significantly improve the speed and accessibility of bacterial diagnostics in clinical and environmental settings.