This article reports for the first time a high-throughput microfluidic system with fully integrated loop-mediated isothermal amplification (LAMP) analysis. With the developed system, parallel Mycobacterium tuberculosis detections were implemented in polytetrafluoroethylene capillaries through the utilization of droplet technology coupled with magnetic beads. During the analysis, liquid plugs containing different types of sample or reagents are sequentially introduced into the capillaries and made to form droplets therein. The whole analytical process, including DNA extraction, LAMP, and detection of the amplified products were conducted in such droplets. The developed microsystem is able to process 10 samples in parallel. The entire diagnostic procedure, from sample-in to answer-out, can be automatically completed within 50 min with a limit of detection (LOD) of 10 bacteria. This microsystem was evaluated by analyzing clinical samples, and a clinical sensitivity (positive detection rate) of 96.8% and specificity (negative detection rate) of 100% were achieved. The presented capillary LAMP assay features high-throughput and low-cost and thus is a promising tool for rapid tuberculosis diagnosis.

A microfluidic chip was developed for one-step identification and antimicrobial susceptibility testing (AST) of multiple uropathogens. The polydimethylsiloxane (PDMS) microchip used had features of cell culture chamber arrays connected through a sample introduction channel. At the bottom of each chamber, a paper substrate preloaded with chromogenic media and antimicrobial agents was embedded. By integrating a hydrophobic membrane valve on the microchip, the urine sample can be equally distributed into and confined in individual chambers. The identification and AST assays on multiple uropathogens were performed by combining the spatial resolution of the cell culture arrays and the color resolution from the chromogenic reaction. The composite microbial testing assay was based on dynamic changes in color in a serial of chambers. The bacterial antimicrobial susceptibility was determined by the lowest concentration of an antimicrobial agent that is capable of inhibiting the chromogenic reaction. Using three common uropathogenic bacteria as test models, the developed microfluidic approach was demonstrated to be able to complete the multiple colorimetric assays in 15 h. The accuracy of the microchip method, in comparison with that of the conventional approach, showed a coincidence of 94.1%. Our data suggest this microfluidic approach will be a promising tool for simple and fast uropathogen testing in resource-limited settings.