Purification of human interleukin 2 produced from normal human peripheral blood mononuclear cells

We have developed a simple protocol for the routine purification of essentially homogeneous human interleukin 2. The procedures applied include ammonium sulfate precipitation, ACA-54 gel filtration, ultrafiltration and chromatofocusing. The product has a molecular weight of 14 000, as determined by electrophoretic mobility, and is free of interleukin 1, interferon, granulocyte and monocyte stimulating factors, B cell growth factor and phytohemagglutinin. The method is efficient, rapid and reproduceable and provides a helpful method for preparation of IL-2 for biochemical and biological studies at moderate cost and without the use of complex equipment.