Recent Improvement in Miniaturization and Integration of A DNA Analysis System for Rapid Forensic Analysis (Midas)

Integration, portability, and parallel multi-sample processing are some of the most desirable features for advanced forensic DNA analytical systems. Integration leads to “sample-to-answer” systems, which can provide rapid, sensitive, and reproducible DNA analyses. Portability brings the systems directly to the scene of forensic investigations and a capability of parallel multi-sample processing allows an enhanced analysis throughput. In order to achieve the above goals, in 2010 we developed the first version of the integrated microfluidic system for rapid forensic DNA analysis, or MiDAS, followed by the second version in 2012 with improvements on the control systems, microfluidic chip designs, and amplification chemistry. In this short communication, we convey our recent progress toward further integration and miniaturization of microfluidic components. This approach will provide more flexible capacity in analytical throughput as it follows: 1) Monolithic integration of a “sample collector module” within the entire analysis workflow, 2) A multi-layer 3D cartridge design which offers capability of parallel multi-sample processing, increases portability, and reduces footprint, 3) Integration of duckbill valves into the 3D cartridge for fluidic controls among the layers and for elimination of manual sealing procedure after on-cartridge reagents loading, and 4) Improvement of polymer valving and microfluidic circuitry around PCR module for minimizing interactions of the assay reagents and reaction products with the polymer materials to increase the yield and quality of the PCR product.