ABSTRACT
Mouse monoclonal antibodies (Mac 002 and Mac 003) raised against recombinant human Interleukin-2 (rec IL-2), were developed for use as assay and purification reagents. In the Immunoradiometric assay, (IRMA), 125I-Mac 002 is used as tracer, with sheep polyclonal anti-rec IL-2 on the solid phase. This reliably measures rec IL-2 in the range 3-1000 ng/ml. The assay measures natural IL-2 with a lower sensitivity. For some samples of IL-2, the amount detected by IRMA is greater than expected from the biological assays, presumably because there are IL-2 molecules with antigenic, but not biological activity. This is a possible source of variation in the specific activities observed in different preparations of of IL-2. In the purification reagent, Mac 003 is immobilised on sepharose CL-4B to purify recombinant IL-2 from less than 1% in an E. Coli extract, to greater than 90% purity, in a single step with greater than 80% yield.
