The National Institute of Allergy and Infectious Diseases (NIAID) supports research on the basic understanding of immune responses leading to the development of vaccines and novel therapeutic agents for the prevention and treatment of infectious and immune-mediated diseases, and improvements in public health. This research includes support of various reagent facilities, repositories, and databases that provide resources for biomedical researchers. As a part of the research program to improve our understanding of the progression, prevention, and treatment of infectious and immune-mediated diseases, the NIAID supports the NIH Major Histocompatibility Complex (MHC) Tetramer Core Facility. This facility provides synthesis and distribution of soluble MHC tetramer reagents to the global research community.