Digital Sort-Enabled Counting Allows Absolute Electrical Quantification of Target Nucleic Acid.

Area of Science:

• Biotechnology
• Molecular Diagnostics
• Microfluidics

Background:

• Quantitative nucleic acid amplification tests are crucial for diagnostics but often require expensive optical equipment, limiting their use outside laboratories.
• Current methods for nucleic acid quantification face challenges in terms of cost, complexity, and portability for widespread diagnostic applications.

Purpose of the Study:

• To develop a microfluidics platform for binary DNA-amplification-activated droplet sorting and label-free absolute quantification of nucleic acids.
• To demonstrate a novel approach for sensitive nucleic acid detection suitable for point-of-care settings.

Main Methods:

• Implementation of a microfluidics platform integrating loop-mediated isothermal amplification (LAMP) with sorting by interfacial tension (SIFT).
• Utilizing pH changes induced by LAMP reactions to sort positive (amplified) and negative (non-amplified) droplets.
• Employing on-chip electrodes for digital electrical counting of target DNA and RNA within sorted droplets.

Main Results:

• Successful demonstration of binary DNA-amplification-activated droplet sorting on a microfluidics platform.
• Achieved label-free absolute quantification of nucleic acids using the digital sort-enabled counting (DISCO) platform.
• Validated digital electrical counting of target DNA and RNA, showcasing the system's sensitivity.

Conclusions:

• The DISCO platform enables sensitive and absolute nucleic acid quantification without costly optical setups.
• This microfluidics-based approach holds significant promise for advancing nucleic acid testing in point-of-care diagnostics.
• DISCO offers a cost-effective and portable solution for molecular diagnostics, expanding accessibility beyond traditional laboratory settings.