| Bioactivity |
Interferon was titrated with the use of the cytopathic effect inhibition assay as described [Familletti et al. (1981) "A Convenience and Rapid Cytopathic Effect Inhibition Assay for Interferon," in Methods in Enzymology , Vol. 78 (S. Pestka, ed.), Academic Press, New York, 387-394] with the exception that EMCV rather than VSV was used as the challenge. The activity was determined relative to a lab standard of Mu-IFN-alpha A which was calibrated to the NIH Murine IFN-alpha standard (Ga02-901-511). Mouse (L929/EMCV) in this assay the EC 50 for IFN is ~5 U/ml. Lot Activity was derived from multiple determinations in the above assay. Please note that IFN assays vary between labs and assay systems [Meager et al (2001). J. Immunol. Meth. 257:17. Meager and Das (2005) J. Immunol Meth. 306:1]
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