A two-site sandwich radioimmunoassay of human gamma interferon with monoclonal antibodies

Two monoclonal antibodies were raised against human gamma interferon (IFN-γ) derived from E. coli harboring the recombinant cDNA for IFN-γ, and one against a synthetic peptide representing its C-terminus amino acid sequence of 20 residues. The monoclonal antibody against the synthetic peptide reacted either with IFN-γ or the synthetic peptide. One monoclonal anti-IFN-γ did not react with the synthetic peptide, while the other showed a weak binding with the peptide. A 2-site '1-step' radioimmunoassay was developed. The assay was rapid with a sensitivity capable of detecting a few ng/ml of IFN-γ. (Auth.)