Integrated portable biological detection system

This invention relates to devices and methods for performing active, multi-step sample preparation and molecular diagnostic analysis of biological materials. More particularly, it relates to integrated, compact, portable devices for self-contained sample to answer systems. Specifically, this invention relates to a device and method for performing multi-step sample preparation and assay on either two or even a single microchip. Examples of applications for this integrated system include food and/or quality monitoring, diagnosis of infectious diseases and cancers, bone marrow plastesis (e.g., stem cell separation and analysis), and genetics-based identification of individuals for forensic purposes. We have performed separation of bacterial and cancer cells from peripheral human blood in microfabricated electronic chips by dielectrophoresis. The isolated cells were examined by staining the nuclei with fluorescent dye followed by laser induced fluorescence imaging. We have also released DNA and RNA from the isolated cells electronically and detected specific marker sequences by DNA amplification followed by electronic hybridization to immobilized capture probes. Efforts towards the construction of a "laboratory-on-a-chip" system are presented which involves the selection of DNA probes, dyes, reagents and prototyping of the fully integrated portable instrument.