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Microfabricated Capillary Array Electrophoresis Genetic Analyzers for Forensic Short Tandem Repeat DNA Profiling

NCJ Number
Date Published
February 2011
67 pages
This project's ultimate goal was to improve forensic STR identification by developing faster, more reliable, higher throughput, more sensitive, and more integrated technologies.
This project achieved five objectives in the pursuit of this goal. First, it optimized a portable microsystem that includes PCR amplification, sample and standard injection, separation, and fluorescence detection in a single integrated microchip. At a mock crime scene, this device conducted real-time STR analyses using a 9-plex STR kit, including sample collection, DNA extraction, STR analyses, and CODIS database search. Second, the project developed an integrated STR sample cleanup, a concentration method that uses a photopolymerized streptavidin-gel capture chemistry coupled to a simple, improved direct injector geometry to achieve high fluorescence signals (-19-fold) and sensitivity (25 copies of DNA) for STR typing. Third, the project integrated this inline capture injector into the researchers' previous mCAE microsystem in developing a 12-lane capture-CAE microsystem with automated operation for high-throughput and high-sensitivity STR sample analysis. Fourth, the project demonstrated the integration of sequence-specific DNA extraction using a magnetic bead capture structure and the improved post-PCR capture inline injector into the PCR-CE system to form a fully integrated microdevice for rapid forensic STR analysis. Fifth, the project constructed the second-generation bench-top rotary mCAE scanner, the Multi-channel Capillary Array Electrophoresis Portable Analyzer (McCAEPS), with reduced size and operational complexity for integrated STR analysis. The motivation for this project stemmed from technologies developed over the past 15 years as part of the human genome project, as well as through the NIJ (National Institute of Justice) grant awarded in 2004. These technologies include the use of more sensitive energy-transfer fluorescent dye labels, the development of microfabricated capillary array electrophoresis (CAE) separation and fluorescence detection systems, and the integration of sample clean-up and PCR amplification with the separation structures. Extensive figures and 57 references

Date Published: February 1, 2011