Used in immunological research to study B cell development and function due to its role as a biomarker for B lymphocytes. This recombinant Cynomolgus/Rhesus macaque CD19 protein with His Tag facilitates the development and testing of monoclonal antibodies and CAR-T cell therapies targeting CD19 in non-human primate models such as cynomolgus and rhesus macaques. The His Tag allows for easy purification and detection in experimental assays, making it valuable in preclinical studies evaluating therapeutic efficacy and safety.