In situ immunological and DNA probe-based histochemical detection methods have widespread, important biomedical applications in infectious and genetic disease diagnosis, neurobiology, developmental biology, pharmacology and other research. However, radioisotopic detection remains the predominant method of histochemical detection, thus denying researchers the same advantages that non-isotopic methods have offered in other applications. To address this problem, we have begun investigating a novel approach to non-isotopic histochemical labeling and detection based on the unique interaction of components of a low molecular weight signaling system. This detection system would offer several advantages over existing methods, including greatly enhanced sensitivity, lower reagent cost, simplified procedures, and significantly improved reagent stability. To establish the feasibility of developing such a system, Phase I studies will focus on development of substrates that enable detection of the unique ,high affinity interactions described above, optimization of methods for preparing conjugates to detect the interactions, and preliminary testing of conjugate sensitivity. Phase II will focus on applying the system for in situ applications to detect infectious agents such as HHV-6. In Phase III, we will complete development of a user friendly clinical diagnostic test, and will commercialize specific research product applications resulting from the research.Awardee's statement of the potential commercial applications of the research:The resulting technology will provide the basis for Phase III development of various commercial products for 1) clinical diagnostics applications, including specific diagnostics for Human Herpesvirus 6 and other clinically important targets, 2) other applications, including molecular biology research products.National Institute of General Medical Sciences (NIGMS)