Mouse anti-dog IgE monoclonal antibody for IHC, ELISA, FC, IP, WB.. In biology, Immunoglobulin E (IgE) is a class of antibody (or immunoglobulin isotype) that has been found only in mammals. IgE is a monomeric antibody with 4 Ig-like domains (CH1->CH4). It plays an important role in allergy, and is especially associated with type 1 hypersensitivity. IgE has also been implicated in immune system responses to most parasitic worms like Schistosomamansoni, Trichinellaspiralis, and Fasciola hepatica, and may be important during immune defense against certain protozoan parasites such as Plasmodium falciparum. Although IgE is typically the least abundant isotype -blood serum IgE levels in a normal (non-atopic) individual are only 0.05% of the Ig concentration, compared to 10 mg/ml for the IgGs (the isotypes responsible for most of the classical adaptive immune response) -it is capable of triggering the most powerful immune reactions. IgE was discovered in 1966 by the Japanese scientist couple Teruka and Kimishige Ishizaka.