Assessing immune function in HIV pathogenesis and vaccine development requires highly complex immunologic assays utilizing specialized technologies, as well as more routine immunologic laboratory techniques. To address these needs, the Immunology Core will provide CFAR members with access to flow cytometric technologies that are not readily available in the laboratories of most affiliated investigators. Specifically, the core will offer members services for high complexity flow cytometry technologies including (a) flow cytometric cell sorting of nonhazardous and biohazardous specimens in a appropriate BL2+ facility, and (b) complex multi-color flow cytometric analysis (up to 8 parameters). In addition, the core will utilize the extensive experience and expertise within the existing immunology laboratories to support training and access to other more basic immunologic techniques, technologies and laboratory work practices essential for AIDS research.