The G7-26 monoclonal antibody specifically recognizes the constant region of human Immunoglobulin E (IgE). It does not crossreact with other immunoglobulin heavy chain isotypes. IgE exists in a transmembrane form that is expressed by B lymphocytes and serves as an antigen receptor. Soluble IgE is produced and secreted by activated B cells and plasma cells. IgE may bind through its constant region to cell surface receptors, such as the high-affinity (FcεRI) or low-affinity (FcεRII/CD23) receptors for IgE. FcεRI is expressed on mast cells, basophils, and at lower levels, on dendritic cells and monocytes. FcεRII/CD23 is expressed by B cells and by some other cell types including T cells, monocytes, eosinophils, neutrophils, follicular dendritic cells, and Langerhans cells. Crosslinking of Fc receptor-bound IgE antibodies by multivalent antigens or allergens can induce phagocytosis or the cellular release of inflammatory mediators. Although IgE can provide immune protection against pathogenic parasites, it may also play a central role in a variety of allergic disorders.
The antibody was conjugated to BD Horizon™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.