Separation of Dirofilaria immitis allergen from the IgG-inducing antigens

Allergen in crude extract of Dirofilaria immitis was purified and separated from the IgG-inducing antigens by a combination of DEAE-Sephadex A-50 chromatography and Sephadex G-200 gel filtration. The molecular weight of the purified preparation was estimated to be approximately 20,000 by gel filtration. The carbohydrate content of the preparation was apparently low, about 2%. Rats immunized with the allergenic fraction developed only a homocytotropic antibody and no hemagglutination antibody.