The monoclonal antibody 2D7- is a specific marker for basophils detecting- a basophil-specific protein of 7.2-7.5 kDa localized in secretory granules. Activated basophils- have been shown to have a reduced staining with the 2D7 antibody consistent with localization of the antigen- to secretory granules.Basophils are multifunctional haematopoietic cells that- secrete a wide variety of proinflammatory- agents upon activation such as histamine and cytokines. Moreover, basophils can induce IgE production by B cells. Under normal conditions basophils are primarily produced in the bone marrow, whereas mature basophils reside in the circulation and can enter tissues at sites of inflammation. Both basophils and mast cells have been implicated in the pathogenesis of allergic inflammation due to the abundant expression of high affinity receptors for IgE. The 2D7 antibody can be used- as a sensitive and precise marker for human basophils- and does not react with lymphocytes, monocytes, eosinophils, neutrophils- or mast cells in immunohistochemistry. Moreover, the antibody is suitable for western blot analysis of the 2D7 antigen.