Compartmentalized Suspension Array for the Isothermal, Digital, and Multiplex Detection of microRNAs

Area of Science:

• Biotechnology and Molecular Diagnostics
• Genomics and Bioinformatics
• Biomarker Discovery

Background:

• Accurate microRNA detection is crucial for disease biomarker identification.
• Current methods like microarrays and next-generation sequencing lack sensitivity and accuracy.
• Digital bioassays offer sensitivity but limited multiplexing.

Purpose of the Study:

• To introduce Digiplex, a novel microRNA profiling procedure.
• To combine the multiplexing capacity of suspension arrays with digital flow cytometry accuracy.
• To achieve sensitive and accurate detection of microRNA panels.

Main Methods:

• MicroRNAs are captured on DNA-grafted particles, following a Poisson distribution.
• Particles are isolated in microfluidic droplets for single-molecule detection.
• Isothermal exponential amplification triggers a fluorescent probe, read by flow cytometry.

Main Results:

• The Digiplex workflow was optimized using a single microRNA model.
• A 10-plex assay demonstrated femtomolar sensitivity.
• The method was validated on total RNA samples and benchmarked against droplet digital PCR.

Conclusions:

• Digiplex successfully integrates multiplexing and digital quantification for microRNA profiling.
• The method achieves high sensitivity and accuracy, outperforming existing techniques.
• Digiplex is a promising tool for disease biomarker discovery and diagnostics.