Electromagnet-actuated droplet platform for sample-to-answer genetic detection

This paper presents a magnetically actuated droplet platform for automated sample preparation and gene detection. Our platform integrates nucleic acid extraction using silicacoated magnetic particles with real-time polymerase chain reaction (PCR) on a single cartridge. The device consists of seven compartments in which reagent droplets are serially loaded. The assay utilizes solid phase nucleic acid isolation chemistry in order to purify genomic DNA from crude samples and elute the material in a PCR-ready buffer. Silicacoated magnetic particle provides a mobile solid phase that can be merged with and removed from reagents efficiently using a combination of planar coils and surface topographical features. Each droplet operation was characterized and evaluated. Using our platform, automated sample processing from whole blood to PCR-ready droplet, followed by amplification was performed successfully. This work demonstrates a fully integrated genetic assay platform for simple and efficient droplet manipulation.