The Virology Laboratory Core provides virologic, immunologic, and molecular diagnostic testing for HSV and HIV-1 in 3 laboratories: 1) The UW Virology Laboratory at Children's Hospital and Regional Medical Center ("UW-CHRMC"; Section Director: R. Ashley). This laboratory will provide HSV and HIV-1 serology, HSV isolation, HSV and HIV-1 antiviral sensitivity testing, and specimen banking, for the HSV Serology and Isolation Section -; 2) The UW-Molecular Virology Laboratory in the SCCA Building at the Fred Hutchinson Cancer Research Center's (FHCRC) South Lake Union (SLU) campus (Section Director: L. Corey) will perform HSV PCR testing for all 3 projects and will develop rapid HSV PCR tests. This is the HSV PCR Section of Laboratory Core; 3) The UW Retrovirus Pathogenesis Laboratory in the Rosen building of the UW SLU campus will provide HIV-1 testing to detect and quantify HIV-1 in tissues, cells and mucosal secretions (Section Director: S. Brodie). These laboratories are well established, accredited diagnostic laboratories; licensed by the State of Washington and certified by the College of American Pathologists and ACTG. The HSV Laboratories will provide centralized support for defining sub clinical and incident HSV infection using state-of-the-art antibody and HSV PCR testing. The Retrovirus Laboratory will provide analyses for HIV-1 infection and replication in blood and mucosal lymphoid tissues and mucosal secretions using newly developed assays that quantitate the frequency and amount of HIV-1 expressed in HIV-1 infected cells. Dr. Koelle and Dr. Brodie's laboratories will collaborate to co-Iocalize HIV-1 and HSV in mucosal and HSV skin lesions in parallel with measurements of cytokines, chemokines and hormone receptor proteins. All Core laboratories share basic protocols for specimen transport, accessioning, tracking, and resulting. Computerized database entry is standardized and coordinated with Statistical Core for data analyses.