Design of a Digital LAMP Detection Platform Based on Droplet Microfluidic Technology

Loop-mediated isothermal amplification (LAMP) is a rapid and high-yield amplification technology for specific DNA or RNA molecules. In this study, we designed a digital loop-mediated isothermal amplification (digital-LAMP)-functioning microfluidic chip to achieve higher sensitivity for detection of nucleic acids. The chip could generate droplets and collect them, based on which we could perform Digital-LAMP. The reaction only took 40 min at a constant temperature of 63 degrees C. The chip enabled highly accurate quantitative detection, with the limit of detection (LOD) down to 10(2) copies mu L-1. For better performance while reducing the investment of money and time in chip structure iterations, we used COMSOL Multiphysics to simulate different droplet generation ways by including flow-focusing structure and T-junction structure. Moreover, the linear structure, serpentine structure, and spiral structure in the microfluidic chip were compared to study the fluid velocity and pressure distribution. The simulations provided a basis for chip structure design while facilitating chip structure optimization. The digital-LAMP-functioning chip proposed in the work provides a universal platform for analysis of viruses.

Automated summary

This study developed a digital loop-mediated isothermal amplification (digital-LAMP) microfluidic chip to enhance the sensitivity of nucleic acid detection. The chip could generate and collect droplets for digital-LAMP reactions, which only took 40 minutes at a constant temperature of 63 degrees C. The chip enabled highly accurate quantitative detection with a detection limit of 10(2) copies/μL. COMSOL Multiphysics was used to simulate different droplet generation methods and analyze the fluid dynamics in the microfluidic chip, providing a basis for chip structure design and optimization. The digital-LAMP-functioning chip proposed in this work offers a universal platform for virus analysis.