Product Information

Description: Recombinant Mouse Interferon Alpha A (Mouse IFN-αA)

Contents: ≥ 1 x 10⁵ units/vial

Volume: 0.1ml

Concentration: ≥ 1 x 10⁶ units/ml

Endotoxin: < 1 EU/µg

Buffer: Phosphate Buffered Saline (PBS) containing 0.1% bovine serum albumun (BSA)

Molecular Weight: 19.5 kDa

Purity: >95%

Purification Method: A combination of ion exchange, hydrophobic interaction and size exclusion chromatography.

Source:Murine (C57/Bl) DNA expressed in E. coli

Synonyms: none

Accession Number: NM_010504

Assay Used to Measure 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-aA which was calibrated to the NIH Murine IFN-α standard (Ga02-901-511). Mouse (L929/EMCV) in this assay the EC50 for IFN is ~ 5U/ml. Specific Activity (refer to Lot Specific C.O.A) x 10⁸ units/mg.

Shipping Information

Shipping Conditions: Dry ice

Physical State of Product During Shipping: Frozen

Special Conditions/Comments: 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).

Product Information: Most mammalian species have multiple IFN-α subtypes. Although the reasons for these multiple subtypes are not fully known, there are clear cell type and temporal differences in their expression. A recent study established a nomenclature for the murine IFN-α subtypes (van Pesch et al. 2004) and determined relative activities of the subtypes with protein quantification by phosphorimaging of metabolically-labeled protein. In this study, Mu IFN-α4 was deemed to have average antiviral activity when compared with the potency of the other subtypes.

Mu IFN-α4 was initially cloned by Zwarthoff et al. [(1985) Nuc. Acids Res. 13(3) 791], and has been extensively studied. It is apparently expressed early in viral infection in a protein synthesis independent manner, and its expression is induced by phosphorylation of IRF-3. It may be that Mu IFN-α4, like IFN-β, has a priming function on cells, enabling the expression of other Mu IFN-α subtypes [Reviewed by Mesplède et al. (2003) Autoimmunity 36(8):447 and Asselin-Paturel & Trinchieri (2005) J. Exp. Med. 202(4):461]. Thus, this interferon is among the first observed after viral infection. Intriguingly, while this interferon is expressed in a large variety of cell types, one report suggests that the expression level in dendritic cells is low to non-existent [Barchet et al. (2002) J. Exp. Med. 195(4):507]

Summary: Mu IFN-α4 is a widely expressed Mu IFN-α which may play a major role in preparing cells to express high levels of other Mu IFN-α subtypes upon viral challenge.



Figure 1: The activity of Mu Alpha-A and Mu Alpha-4 was compared in an L929/EMCV CPE assay. The EC₅₀ for Mu Alpha-A in this experiment was 54 pg/ml while the EC₅₀ for Mu Alpha-4 was 37 pg/ml. Similar results were obtained for several batches of Mu Alpha-4. Results are representative and may vary depending upon experimental conditions.

This Product is for RESEARCH USE ONLY and is not for sale or use in any commercial kit or for use in the preparation of any commercial antibody. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE, OR USE IN HUMANS.

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