The specific aim of this proposal is the purchase of an Applied Biosystems 7900HT High Throughput Real-Time PCR System for the Microarray Core at the University of Arkansas for Medical Sciences. The instrument is required for 12 NIH-funded projects of 7 principle investigators including Drs. Barger, Griffin, Kern, Lecka-Czernik, Mock, McGehee, Peterson, and other Microarray Core clientele including BRIN, and GCRC sponsored projects. The instrument is justified because: (1) The noted users and Core will investigate a number of samples (>2138) and genes (>455) of interest in 2006-2007 and beyond that will necessitate high-throughput capabilities; (2) the 7900HT is the only commercially available instrument that can continuously run real-time PCR 384-Well reaction plates overnight and collect and merge the data; (3) the 7900HT will be the only high-throughput PCR system in the state of Arkansas; (4) the 7900HT offers the greatest flexibility to allow individual investigators to balance assay cost and labor intensiveness to meet their needs; (5) use of the current instrument, the 7700, will reach maximum capacity in 2005 and service contracts will not be offered after April 2007; (6) adding another Applied Biosystems instrument will provide experimental continuity and will limit the training time needed for major users; and (7) it is expected that the 7900HT will be just as reliable for and tolerant of a large number of users as the 7700 which experienced less than 2-weeks cumulative down time since 2001 making it especially appropriate for integration into a core facility. The PI is qualified to be responsible for the instrument as he has co-authored 5 peer-reviewed research articles utilizing real-time PCR, developed optimization procedures for SYBR green assays that cost 12% of those recommended by Applied Biosystems and has personally designed assays for more than 170 human, rat, and mouse genes with nearly a 100% success rate. An Advisory Committee will meet twice yearly or as needed to assure equitable and compliant usage. The institution has committed more than $50,000 to the management and maintenance of the 7900HT PCR System. The instrument will benefit public health as it is a valuable research tool to investigate regulation of biological pathways and the pathological consequences of their dysregulation. Specifically, priority projects are in areas of widespread significance: Alzheimer's disease and Down's syndrome, metabolic syndrome and diabetes, osteoporosis and skeletal muscle frailty, vitamin deficiency, and cancer. ? ? ?