First, the selection and optimization of a DNA extraction and purification protocol was completed with the selection of a guanidinium chloride (GuHCI) and silica-based extraction and purification protocol for microfluidic purification. Second, the selection and optimization of a DNA extraction and purification media was completed with the selection of a commercially available silica fiber membrane that allows purification of DNA from large volumes (in excess of 1 ml) of whole blood with an efficiency of approximately 70 percent. Third, the design and fabrication of the microfluidic extraction and purification biochip milestone was completed with the successful fabrication, demonstration, and optimization of a microfluidic biochip and protocol that can purify multiple samples simultaneously in 8 minutes. The biochip has a demonstrated capacity of over 10 mg and a purification efficiency of over 50 percent for blood input volumes of less than 100 ml. Fourth, biochip DNA extraction and purification from mock crime scene and database samples was completed with the successful DNA purification and subsequent successful inhibitor-free multiplex PCR amplification of blood, saliva, and cellular samples from cotton swabs; touch samples from cotton swabs; blood and saliva on cotton, denim, and polyester; and buccal cells from swabs. 31 figures, 3 tables, and 29 references