Forensic DNA Analysis

A central challenge of genomics is to detect sequence variations using simple and reliable high-throughput technology. We have developed a system based on the physical concept of branch migration for mutation detection and forensic-related individual identification. Branch migration is a key step in many homologous recombination DNA processes: a single DNA strand extends its partial pairing with its complementary strand as it displaces the resident strand from a DNA duplex.  We applied branch migration to a microarray-based short tandem repeat (STR) fingerprinting system, allowing rapid identification of very small amounts of DNA extracted from various tissues. In addition, inhibiting complementary strand displacement allows the identification of single nucleotide changes. To increase the sensitivity of the method we implemented branch migration assay in suspension bead array, a bead-based detector system (Luminex suspension array technology).

Pyrosequencing is a widely applicable, alternative technology for interrogating STRs and has the potential advantages of accuracy, flexibility, parallel processing, and facile automation. We intend to use Pyrosequencing for STRs analysis. Given the throughput capabilities of pyrosequencing, this system has the potential to enhance the use of microsatellites in forensic criminology, paternity testing and Cancer diagnostics.