Detection of hybridomas secreting monoclonal antibodies to human gamma interferon using a rapid screening technique and specificity of certain monoclonal antibodies to gamma interferon.

An immunoprecipitation technique, which uses radiolabeled human gamma interferon (HuIFN-gamma) and a sheep anti-mouse F(ab')2 serum, is described for the rapid detection of mouse monoclonal antibodies to IFN-gamma in hybridoma culture supernatants. This technique which can be performed in 4 h detects both neutralizing and nonneutralizing antibodies to IFN-gamma. Certain monoclonal antibodies prepared against natural (glycosylated) IFN-gamma which neutralized the antiviral activity of natural IFN-gamma bound strongly to rDNA (unglycosylated) IFN-gamma derived from E. coli, but failed to neutralize its antiviral activity.