E. coli-derived human IL-4 protein His25-Ser153, with an N-terminal Met Produced using non-animal reagents in an animal-free laboratory.
>97%, by SDS-PAGE under reducing conditions and visualized by silver stain.
<0.01 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Predicted Molecular Mass
14 kDa, reducing conditions
Measured in a cell proliferation assay using TF‑1 human erythroleukemic cells. Kitamura, T. et al. (1989) J. Cell Physiol. 140:323. The ED50 for this effect is 0.05-0.2 ng/mL. The specific activity of Recombinant Human IL-4 is approximately 2.9 x 104 IU/μg, which is calibrated against human IL-4 WHO International Standard (NIBSC code: 88/656).
Recombinant Human IL-4, Animal-Free Protein Scientific Data Examples
Recombinant Human IL-4, Animal-Free Protein Bioactivity
Animal-FreeTM Recombinant Human IL-4 (Catalog # AFL204) stimulates cell proliferation of the TF-1 human erythroleukemic cell line. The ED50 for this effect is 0.05-02 ng/mL.
Recombinant Human IL-4, Animal-Free Protein SDS-PAGE
1 μg/lane of Animal-FreeTMRecombinant Human IL-4 (Catalog # AFL204) was resolved with SDS-PAGE under reducing (R) conditions and visualized by silver staining, showing a single band at 14 kDa.
Formulation, Preparation and Storage
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant
protein to be stored at a more dilute concentration.
The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or
as an ELISA standard.
In contrast, the carrier free protein is recommended for applications, in which the presence of BSA
Lyophilized from a 0.2 μm filtered solution in PBS.
Reconstitute at 0.2 mg/mL in sterile PBS.
The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage:
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
12 months from date of receipt, -20 to -70 °C as supplied.
1 month, 2 to 8 °C under sterile conditions after reconstitution.
12 months, -20 to -70 °C under sterile conditions after reconstitution.
Interleukin-4 (IL-4), also known as B cell-stimulatory factor-1, is a monomeric, approximately 13 kDa‑18 kDa Th2 cytokine that shows pleiotropic effects during immune responses (1‑3). It is a glycosylated polypeptide that contains three intrachain disulfide bridges and adopts a bundled four alpha -helix structure (4). Human IL-4 is synthesized with a 24 aa signal sequence. Alternate splicing generates an isoform with a 16 aa internal deletion. Mature human IL-4 shares 55%, 39% and 43% aa sequence identity with bovine, mouse, and rat IL-4, respectively. Human, mouse, and rat IL-4 are species-specific in their activities (5‑7). IL-4 exerts its effects through two receptor complexes (8, 9). The type I receptor, which is expressed on hematopoietic cells, is a heterodimer of the ligand binding IL-4 R alpha and the common gamma chain (a shared subunit of the receptors for IL-2, -7, -9, -15, and ‑21). The type II receptor on nonhematopoietic cells consists of IL-4 R alpha and IL‑13 R alpha 1. The type II receptor also transduces IL-13 mediated signals. IL-4 is primarily expressed by Th2-biased CD4+ T cells, mast cells, basophils, and eosinophils (1, 2). It promotes cell proliferation, survival, and immunoglobulin class switch to IgG4 and IgE in human B cells, acquisition of the Th2 phenotype by naïve CD4+ T cells, priming and chemotaxis of mast cells, eosinophils, and basophils, and the proliferation and activation of epithelial cells (10‑13). IL-4 plays a dominant role in the development of allergic inflammation and asthma (12, 14).
Benczik, M. and S.L. Gaffen (2004) Immunol. Invest. 33:109.
Chomarat, P. and J. Banchereau (1998) Int. Rev. Immunol. 17:1.
Yokota, T. et al. (1986) Proc. Natl. Acad. Sci. 83:5894.
Redfield, C. et al. (1991) Biochemistry 30:11029.
Ramirez, F. et al. (1988) J. Immunol. Meth. 221:141.
Leitenberg, D. and T.L. Feldbush (1988) Cell. Immunol. 111:451.
Mosman, T.R. et al. (1987) J. Immunol. 138:1813.
Mueller, T.D. et al. (2002) Biochim. Biophys. Acta 1592:237.
Nelms, K. et al. (1999) Annu. Rev. Immunol. 17:701.
Paludan, S.R. (1998) Scand. J. Immunol. 48:459.
Corthay, A. (2006) Scand. J. Immunol. 64:93.
Ryan, J.J. et al. (2007) Crit. Rev. Immunol. 27:15.
Grone, A. (2002) Vet. Immunol. Immunopathol. 88:1.
Rosenberg, H.F. et al. (2007) J. Allergy Clin. Immunol. 119:1303.
Animal-Free Manufacturing Conditions Our dedicated controlled-access animal-free laboratories ensure that at no point in production are the products exposed to potential contamination by animal components or byproducts. Every stage of manufacturing is conducted in compliance with R&D Systems' stringent Standard Operating Procedures (SOPs). Production and purification procedures use equipment and media that are confirmed animal-free.
All molecular biology procedures use animal-free media and dedicated labware.
Dedicated fermentors are utilized in committed animal-free areas.
Protein purification columns are animal-free.
Bulk proteins are filtered using animal-free filters.
Purified proteins are stored in animal-free containers in a dedicated cold storage room.
Low Endotoxin Level.
No impairment of biological activity.
High quality product obtained under stringent conditions.
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments and Simple Plex Assays are available to quote. ProteinSimple branded instrument consumables and ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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