The 2E2 antibody recognizes the extracellular region of the 90 kDa alpha chain subunit of the mouse interferon-γ receptor (IFN-γRα, aka, CD119). The functionally active-form of the mouse IFN-γ receptor consists of two (or more) subunits, with IFN-γRα responsible for IFN-γ binding and both the IFN-γRα and IFN-γRβ chains required for the transduction of biologic responses. IFN-γRα is expressed by a variety of cell lines and normal mouse cells (except mature erythrocytes) including T cells, B cells, NK cells, monocytes, neutrophils, fibroblasts, epithelial and endothelial cells. The 2E2 antibody is a non-neutralizing antibody, it does not block the binding of IFN-γ to its receptor. The immunogen used to generate this hybridoma was a purified preparation of soluble recombinant mouse IFN-γRα chain protein. This antibody is routinely tested by flow cytometric analysis. Other applications were tested during antibody development only or reported in the literature. Expression of cell surface IFN-γRα by BALB/c splenic lymphocytes. RBC-lysed BALB/c spleen cells were preincubated (~15 minutes, 4 °C) with purified 2.4G2 antibody [rat anti-mouse CD16 (FcγIII)/CD32 (FcγII), Cat. No. 553142, 1 μg antibody/10e6 cells]. The cells were stained (30 minutes, 4 °C) with biotinylated 2E2 antibody (1 μg mAb/10e6 cells, Cat. No. 550482) followed by R-PE-conjugated streptavidin (Cat. No. 554061, 0.015 μg PE-SA/10e6 cells). After washing, the cells were analyzed with a FACScan™ Flow Cytometer. The immunofluorescent staining patterns for cells stained with either biotinylated 2E2 antibody (filled histogram) or Streptavidin-PE (background staining, empty histogram) are shown. The histograms were generated from reanalyzed flow cytometric data files that were gated for events with the light-scattering characteristics of lymphocytes.