Interferon-(gamma) (IFN-(gamma)) is a soluble cytokine produced primarily by activated Th1 cells, and also by CD8 T cells, natural killer (NK), and natural killer T (NKT) cells. It is the prototypic Th1 cytokine with multiple immune regulatory functions including enhancing the antigen presentation and pathogen-killing functions of macrophages, inducing the production of IgG2a and IgG2b isotype antibodies by B cells, and promoting Th1 T cell differentiation while suppressing Th2 T cell differentiation. IFN-(gamma) is especially important in the macrophage-mediated natural defense against infection by intracellular pathogens, including Mycobacteria species. Cayman's INF-(gamma) (mouse) EIA Kit is an immunometric (i.e., sandwich) EIA that permits INF-(gamma) measurements within the range of 0-500 pg/ml, with a limit of detection of 7.8 pg/ml.