An integrated array-based emulsion droplet microfluidic device for digital loop-mediated isothermal amplification (LAMP) analysis

Loop-mediated isothermal amplification (LAMP) is a nucleic acid amplification technique which amplifies DNA with high specificity, efficiency and rapidity under isothermal conditions. In this study, a microfluidic droplet-array chip is presented to implement array-based digital LAMP analysis. The proposed microfluidic system can perform the basic operation of droplets including droplet formation, droplet immobilization, LAMP and detection. This is the first time that an emulsion-droplet microfluidic device was used for array-based digital LAMP analysis. When compared to micro-well digital PCR assays, this droplet array-based digital LAMP assay eliminates the constraint on the size of the digitized target, which was determined by the dimension of the micro-wells. Moreover, the employment of hydrodynamic trapping allows for one-droplet-to-one-trap operation. This microfluidic chip may become a promising device for digital LAMP based diagnosis.