[Interferon: A greatly simplified immuno enzyme determination with two monoclonal antibodies].

Human leukocyte interferon (HuIFN-alpha) can be determined by a substantially simplified enzyme-immunological method, based on the solid phase sandwich principle. In a single step, the interferon in the sample or the standard solution (tests and standards are run concomitantly) is bound to a polystyrene bead coated with monoclonal (mouse) anti-interferon, and at the same time it is labelled with a second monoclonal (mouse) interferon antibody, which is coupled to horse radish peroxidase. After this immunological incubation, the non-bound material is removed by washing, and the quantity of peroxidase bound to the bead is measured enzymically. The resulting colour intensity is determined photometrically, and it is directly proportional to the interferon concentration in the sample. The detection limit of the test can be as low as 100 I.U./l interferon, depending on the assay conditions. The variation coefficient within series was 3-6%. Serum samples can be used directly in the test without pretreatment. Depending on the required sensitivity, the incubation may be performed for periods between 30 minutes and 24 hours.