Mouse Interferon Beta, mammalian

After receipt, this product should be kept at -70°C or below for retention of full activity. Thaw product vial by incubation in cold tap water until just thawed – the contents of the tube should be apportioned in separate tubes so that freezing and thawing is kept to a minimum. Refreezing should be done on dry ice or in a dry ice/alcohol bath. Further dilution of the product should be in buffers containing protein such as 0.1% bovine serum albumin (BSA) .

Assay Used to Measure Bioactivity: Interferon was titrated with the use of the cytopathic effect inhibition assay as listed. Mouse (L929/EMCV) -performed as described [Rubinstein et al. (1981) J. Virol. 37 (2) :755]. The EC50 for interferon in this assay is ~ 2.5 U/ml. Lot Activity was derived from multiple determinations in the above assay. The units are determined by use of a Mu IFN-β laboratory standard calibrated to the international reference standard for mouse Interferon Beta provided by the National Institutes of Health [Meager et al. (2001) J. Immunol Methods. 257 (1-2) :17-33]. 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].