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Recombinant human IL-6 protein

QK093

Brand: Qkine

Interleukin-6 (IL-6) is a multifunctional cytokine that regulates immune responses and inflammation. It is produced by various cells, including immune cells such as T cells and macrophages, as well as non-immune cells like fibroblasts and endothelial cells. 

Human IL-6 has a molecular weight of 20.9 kDa. This protein is animal origin-free, carrier-free and tag-free to ensure its purity with exceptional lot-to-lot consistency. IL-6 is suitable for the culture of reproducible and high-quality hematopoietic stem cells and other relevant cells. 

Qkine 3-for-2 product campaign

Currency: 

Product name Catalog number Pack size Price Price (USD) Price (GBP) Price (EUR)
Recombinant human IL-6 protein, 25 µg QK093-0025 25 µg (select above) $ 280.00 £ 205.00 € 240.00
Recombinant human IL-6 protein, 50 µg QK093-0050 50 µg (select above) $ 410.00 £ 305.00 € 357.00
Recombinant human IL-6 protein, 100 µg QK093-0100 100 µg (select above) $ 620.00 £ 455.00 € 532.00
Recombinant human IL-6 protein, 500 µg QK093-0500 500 µg (select above) $ 2,500.00 £ 1,840.00 € 2,150.00
Recombinant human IL-6 protein, 1000 µg QK093-1000 1000 µg (select above) $ 3,950.00 £ 2,900.00 € 3,388.00

Note: prices shown do not include shipping and handling charges.

Qkine company name and logo are the property of Qkine Ltd. UK.

Alternative protein names

B-cell stimulatory factor 2 (BSF-2)
CTL differentiation factor (CDF)
Hybridoma growth factor
Interferon beta-2 (IFN-beta-2)

Species reactivity

human

species similarity:
mouse – 39%
rat – 38%
porcine – 59%
bovine – 55%

Frequently used together with:

Summary

  • High purity human protein (Uniprot number: P05231)
  • >98%, by SDS-PAGE quantitative densitometry
  • Source: Expressed in E. coli
  • 20.9 kDa monomer
  • Animal origin-free (AOF) and carrier protein-free
  • Manufactured in Cambridge, UK
  • Lyophilized from HEPES/NaCl
  • Resuspend in water at >100 µg/mL, prepare single-use aliquots, add carrier protein if desired, and store frozen at -20°C or -80°C
Handling and Storage FAQ

Featured applications

  • Immune response regulation 
  • Stimulation of B cell differentiation 
  • Stimulation of T cell differentiation 
  • Hematopoiesis regulation 
  • Proliferation and differentiation of erythrocytes, leukocytes and platelets 
  • Inflammation amplification 

Bioactivity

Bioactivity graph showing the EC50 of 2.46 pg/ml (70 pM) for Qkine recombinant IL-6

IL-6 protein activity is determined using the IL-6-responsive firefly luciferase reporter assay. Transfected HEK293T cells are treated in triplicate with a serial dilution of IL-6 for 24 hours. Firefly luciferase activity is measured and normalised to the control Renilla luciferase activity. Data from Qk093 lot #204594. EC50 = 1.46 ng/mL (70 pM) 

Purity

SDS-PAGE gel showing the high purity reduced and non-reduced forms of IL-6 

Recombinant IL-6 migrates as a major band at approximately 20 kDa in non-reducing (NR) and at approximately 18 kDa in reduced (R) conditions. No contaminating protein bands are present. The purified recombinant protein (3 µg) was resolved using 15% w/v SDS-PAGE in reduced (+β-mercaptoethanol, R) and non-reduced (NR) conditions and stained with Coomassie Brilliant Blue R250. Data from Qk093 lot #204599. 

Further quality assays

  • Mass spectrometry, single species with the expected mass
  • Endotoxin: <0.005 EU/μg protein (below the level of detection)
  • Recovery from stock vial: >95%

Qkine IL-6 is more biologically active than a comparable alternative supplier protein

Quantitative luciferase assay with Qkine IL-6 (Qk093, green) and alternative supplier IL-6 (Supplier B, black). Cells were treated in triplicate with a serial dilution of IL-6 for 24 hours. Firefly luciferase activity was measured and normalized to control Renilla luciferase activity. Qk093 EC50 1.85 ng/ml, Supplier B EC50 5.74 ng/ml.

Qkine IL-6 is stable and bioactive up to 28 days in cell culture conditions

A

IL-6 day 28 bioactivity

B
IL-6 SDS page gel showing stability

Stimulation of proliferation of TF-1 cells with Qkine IL-4 (Qk092, green) and alternative supplier IL-4 (Supplier B, black). Cells were treated in triplicate with a serial dilution of IL-4 for 72 hours and proliferation measured using the CellTiter-Glo (Promega) luminescence assay.

Protein background

Interleukin-6 (IL-6) is a multifunctional cytokine that plays a crucial role in regulating the immune response, inflammation, and various physiological processes. IL-6 is produced by a variety of cells, including T cells, B cells, monocytes, fibroblasts, endothelial cells, and adipocytes [1].

IL6 protein is a pleiotropic cytokine that belongs to the interleukin family of proteins. IL-6 adopts a four-helix bundle structure, with helices A and D forming the receptor-binding site [2]. It is glycosylated, influencing stability and activity. IL-6 binds to IL-6 receptor (IL-6R), forming a hexameric complex with gp130, initiating downstream signaling via the JAK/STAT pathway. Conformational changes upon receptor binding facilitate signaling.

IL-6 has a primary involvement in the acute phase response, the immediate reaction to infection, injury, or inflammation. IL-6 stimulates the production of acute-phase proteins such as C-reactive protein (CRP), fibrinogen, and serum amyloid A, which help to enhance the immune response and facilitate tissue repair [3,4].

IL6 protein plays a key role in the regulation of the immune system. It promotes the differentiation of B cells into antibody-producing plasma cells and stimulates the proliferation and activation of T cells, enhancing the adaptive immune response. IL-6 acts on various immune cells to modulate inflammation, promoting the recruitment of immune cells to sites of infection or injury [5,6]. IL-6 has diverse effects on different tissues and organs throughout the body. It has been implicated in the regulation of metabolism, with studies suggesting that IL-6 may play a role in energy balance, glucose metabolism, and lipid metabolism. IL-6 has been shown to have both pro- and anti-inflammatory effects depending on the context and the cells involved [7].

Dysregulated IL-6 signaling has been associated with various pathological conditions, including autoimmune diseases, chronic inflammation, and cancer. Elevated levels of IL-6 have been observed in conditions such as rheumatoid arthritis, systemic lupus erythematosus, and inflammatory bowel disease, where it contributes to tissue damage and disease progression [8].

Background references

  1. Rose-John, S., & Heinrich, P. C. Soluble receptors for cytokines and growth factors: generation and biological function. Biochem. J. 436, 241–259 (2012).
  2. Kishimoto, T. Interleukin-6: Discovery of a pleiotropic cytokine. Arthritis Res. Ther. 12(Suppl 1), S2 (2010).
  3. Tanaka, T., Narazaki, M. & Kishimoto, T. Interleukin-6: From bench to bedside. Nat. Rev. Immunol. 20, 230–244 (2020).
  4. Scheller, J., Chalaris, A., Schmidt-Arras, D., & Rose-John, S. The pro- and anti-inflammatory properties of the cytokine interleukin-6. Biochim. Biophys. Acta – Mol. Cell Res. 1813, 878–888 (2011).
  5. Hunter, C. A., & Jones, S. A. IL-6 as a keystone cytokine in health and disease. Nat. Immunol. 16, 448–457 (2015).
  6. Rincon, M. Interleukin-6: from an inflammatory marker to a target for inflammatory diseases. Trends Immunol. 33, 571–577 (2012).
  7. Tanaka, T. & Kishimoto, T. The biology and medical implications of interleukin-6. Cancer Immunol. Res. 2, 288–294 (2014)
  8. Jones, S. A. & Jenkins, B. J. Recent insights into targeting the IL-6 cytokine family in inflammatory diseases and cancer. Nat. Rev. Immunol. 18, 773–789 (2018).