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Human Interleukin-28A (hIL-28A/IFN-λ2)

Human Interleukin-28A (hIL-28A/IFN-λ2) #5164

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Citations (1)

The bioactivity of hIL-28A was determined in a virus protection assay. Hep G2 cells were pre-treated with increasing concentrations of hIL-28A for 24 hours. Cells were then inoculated with encephalomyocarditis virus (EMCV) and incubated for an additional 48 hours. Surviving cells were fixed and stained with crystal violet and the OD595 was determined.

The purity of recombinant hIL-28A was determined by SDS-PAGE of 6 µg reduced (+) and non-reduced (-) recombinant hIL-28A and staining overnight with Coomassie Blue.

Western blot analysis of extracts from Hep G2 cells, untreated or treated with hIL-28A for 30 minutes, using Phospho-Stat3 (Tyr705) (D3A7) Rabbit mAb #9145 (upper) and Stat3 Antibody #9132 (lower).


With carrier: Lyophilized from a 0.22 μm filtered solution of PBS, pH 7.2 containing 20 μg BSA per 1 μg hIL-28A. Carrier free: Lyophilized from a 0.22 μm filtered solution of PBS, pH 7.2.


Stable in lyophilized state at 4°C for 1 year after receipt. Sterile stock solutions reconstituted with carrier protein are stable at 4°C for 2 months and at -20°C for 6 months. Avoid repeated freeze-thaw cycles.Maintain sterility. Storage at -20°C should be in a manual defrost freezer.

Product Description


>98% as determined by SDS-PAGE of 6 μg reduced (+) and non-reduced (-) recombinant hIL-28A. All lots are greater than 98% pure.

Molecular Formula:

Based on amino acid sequencing, greater than 60% of recombinant hIL-28A starts at Val26 (VPVAR) and has a calculated MW of 19,754. The remainder starts at Pro27 (PVARL) or Val28 (VARLH). DTT-reduced and non-reduced protein migrate as 21 kDa polypeptides.


The bioactivity of recombinant hIL-28A was determined in a virus protection assay. The ED50 of each lot is between 10-60 ng/ml.


Less than 0.01 ng endotoxin/1 μg hIL-28A.

Source / Purification

Recombinant human IL-28A (hIL-28A) Val26-Val200 (Accession #NP_742150) was expressed in human 293 cells at Cell Signaling Technology.


IL-28A is a member of the Interferon λ family of cytokines, which includes IL-29 and IL-28B (1). IL-28A is produced by a number of cell types and shares many functions with Type I Interferons (1-3). IL-28A exhibits anti-viral activities in vitro and in vivo (1,2). IL-28A directly inhibits tumor cell proliferation and promotes anti-tumor immune responses in vivo (1,3). The IL-28 receptor is a heterodimer of the IL28-Rα and IL10-RI (1). IL-28A activates Stat1, Stat3, and Stat5 (1). IL-28Rα expression is limited to a few cell types, including plasmacytoid DC and epithelial cells (1).

  1. Li, M. et al. (2009) J Leukoc Biol 86, 23-32.
  2. Ank, N. et al. (2006) J Virol 80, 4501-9.
  3. Numasaki, M. et al. (2007) J Immunol 178, 5086-98.

Pathways & Proteins

Explore pathways + proteins related to this product.

For Research Use Only. Not For Use In Diagnostic Procedures.

Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.

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