This technology includes a mouse monoclonal antibody that recognizes the phosphorylated form of the FceRiy which could be used as a diagnostic tool during allergic reactions. The FcERI is central to the activation of mast cells and basophils and activation of this receptor induces these cells to secrete mediators that cause allergic symptoms. This antibody specifically recognizes the phosphorylated tyrosine 47 (Y 47) of the FceRiy. Phosphorylation of this site Indicates that this receptor is in an active state and thus the cells can secrete allergic mediators.