PROJECT SUMMARY/ABSTRACT Investigators at UGA have established national and international recognition for their research on high- containment pathogens of global importance. UGA investigators are working towards understanding pathogenesis and developing newer vaccines, therapeutics and diagnostics to confer sustained immunity to re- challenge with homologous or heterologous pathogen strains. However, to advance these programs, multiparametric flow cytometer with high speed sorting is critical to formulate assays which assess vaccine efficacy, disease transmission, host response, and pre-clinical testing of vaccine/therapeutics/diagnostic candidate(s). This capability is currently lacking at the University of Georgia. The major users for the proposed flow cytometer sorter comprise NIH-funded researchers from three Departments at UGA; Infectious Diseases, Population Health and Pathology. Additional users are investigators of United States Department of Agriculture. Currently, multiple flow cytometers and sorters are available at UGA, and three are equipped with Biosafety Cabinets for sorting infectious cells. However, none of the existing cytometers or sorters can be used for un-fixed/live samples that are processed in high-containment / Biosafety Level-3 (BSL3) or BSL3-Ag laboratories. Acquisition of the proposed flow cytometer-sorter will provide new capabilities that will allow investigators to address complex immunological research problems in the area of infectious diseases. Specific areas of investigation that will directly benefit by obtaining the proposed instrument are: 1) immune response and vaccine development for Brucella melitensis, Mycobacterium tuberculosis, Bordetella spp, influenza virus, SARS-CoV-2 and several others, 2) immune response to Human Immunodeficiency Virus (HIV) – Mycobacterium tuberculosis co-infection, 3) understanding of the transmission of respiratory pathogens, 4) host range and pathogenesis of respiratory viral and bacterial co-infection, 5) pathogenesis and immune response to Burkholderia mallei and Burkholderia pseudomallei and hemorrhagic fever viruses Ebola, Lassa and SARS-CoV-2. The lack of a cytometer-sorter in a high-containment facility has hindered UGA researchers ability to perform critical experiments with highly pathogenic organisms. The instrument will therefore facilitate the realization of research goals and maintenance of NIH support for biomedical research.