The Flow Cytometry Core will be responsible for all BIIR flow cytometry assays performed on blood specimens from U19 study subjects, and sorting of specific cell subsets for biological studies. The Core will also help to organize, archive, and mine flow cytometry data for integration with other data sets and determination of potential biomarkers of successful vaccination and disease protection. This Core will analyze whole blood flow cytometry phenotypes on study subjects, perform cell sorting on subsets to be used for biological assays, and test and maintain database systems for archiving, organizing, and mining flow cytometry data. We will use web-based systems for uploading and annotating flow cytometry experiments, and will test new tools for organizing, sharing, and mining data from these experiments.