Semiquantitative Nucleic Acid Test with Simultaneous Isotachophoretic Extraction and Amplification

Area of Science:

• Biotechnology
• Molecular Diagnostics
• Point-of-Care Testing

Background:

• Nucleic acid amplification tests (NAATs) are crucial for diagnosing infectious diseases and monitoring viral loads.
• Current NAATs often require centralized labs, specialized equipment, and trained personnel, leading to delays in patient care.
• Low-resource settings urgently need accessible, point-of-care (POC) NAAT solutions for timely diagnosis and treatment.

Purpose of the Study:

• To develop a rapid, low-cost, integrated POC NAAT system.
• To enable simultaneous sample preparation and nucleic acid amplification on a paper substrate.
• To demonstrate the feasibility of using electrokinetics with isotachophoresis (ITP) and recombinase polymerase amplification (RPA) for POC diagnostics.

Main Methods:

• Developed a paper-based device integrating electrokinetics for sample preparation and RPA for amplification.
• Utilized simultaneous isotachophoresis (ITP) and recombinase polymerase amplification (RPA) for nucleic acid extraction and amplification.
• Tested the system with serum and whole blood samples, assessing detection limits and speed.

Main Results:

• Achieved consistent detection of as few as 5 copies per reaction in buffer and 10,000 copies/mL in human serum.
• Demonstrated successful preliminary DNA extraction and amplification from whole blood samples.
• Obtained results in under 20 minutes, showcasing the test's rapid nature.

Conclusions:

• The developed POC NAAT system offers high diagnostic accuracy and speed using low-cost materials.
• Integrated ITP and RPA on a paper substrate provides a viable method for POC nucleic acid testing.
• This technology holds significant potential for infectious disease detection and viral load monitoring in resource-limited settings.