Profile: Xeno Diagnostics, LLC is a contract research organization (CRO) specializing in custom cell-based assays in the area of immunological testing. Cell-based assays is a powerful and versatile tool to look at the functional states of various cell types. Properly designed assays can measure many biological functions of interest. We focus primarily on inflammation and immunology, many of the assays we currently have developed are designed to provide insight into the immunologic reaction or status of animals undergoing various therapies. These assays include mixed lymphocyte reactions (MLR’s), cell-dependent complement-mediated cytotoxicity assays, phagocytosis assays, and viability assays. When these cell-based assays are combined with other immunoassays and physiological data, we gain insight into the biological response of the individual being studied. We utilize the flow cytometric analysis of target cells to establish the serum concentration which kills 50% (IC50) of the target cells.