[Technological innovations for the 21st century: synthesis of optical and biotechnologies]

As the population ages in many developing countries, preventive-rather treatment-based medicine would be the key to improved and cost-effective health care in the 21st century. To accomplish this goal, we have developed a fully automated DNA assay system, called "optical rapid assay(ORA)" utilizing and combining micromachine and optical technologies. This system consists of innovative preparatory modules, a free flow electrophoresis for separation of DNA from other contaminants in the specimens, an extremely compact and effective microreactor for PCR, and two reflection null comparative ellipsometry for direct detection of hybridized target DNA without any labelled reagents. The total system will undoubtedly contributes to early diagnosis of serious infections such as viral hepatitis, and future standardization of DNA assays. Simultaneously, each module of the system provides a potential tool for R & D of DNA based diagnoses and therapies.