Recombinant Human IL-6

Recombinant Human IL-6 is widely used in research because it is a bioactive cytokine with critical roles in immune regulation, hematopoiesis, inflammation, and disease modeling. Its recombinant form provides a consistent, defined tool for studying cellular responses and signaling pathways involving IL-6.

Key scientific applications and reasons to use recombinant human IL-6 include:

• Immune Cell Differentiation and Activation: IL-6 promotes the differentiation of B cells and T cells (especially Th17 cells), and stimulates the proliferation of hematopoietic progenitor cells. This makes it essential for studies on adaptive immunity, immune cell development, and cytokine signaling.

• Inflammation and Disease Modeling: As a major mediator of inflammation, IL-6 is involved in chronic inflammatory conditions, autoimmune diseases, and cancer. Recombinant IL-6 is used to model these processes in vitro, enabling mechanistic studies and drug screening.

• Hematopoiesis and Cell Culture: IL-6 supports colony formation from hematopoietic progenitor cells and can replace feeder cells in hybridoma generation, facilitating monoclonal antibody production and stem cell research.

• Bone and Tissue Biology: IL-6 influences bone turnover and osteogenic differentiation, making it valuable for studies on bone metabolism and mesenchymal stem cell biology.

• Functional Assays and Signal Transduction: Recombinant IL-6 is used in cell culture and functional assays to investigate cytokine signaling, gene expression, and cellular responses under controlled conditions.

• Consistency and Reproducibility: The recombinant protein ensures batch-to-batch consistency, defined concentration, and purity, which are critical for reproducible experimental results and quantitative analyses.

In summary, using recombinant human IL-6 allows precise manipulation of cytokine environments in vitro, supports a wide range of immunological, hematopoietic, and disease-related studies, and provides a reliable reagent for functional assays and mechanistic research.

Yes, recombinant human IL-6 can be used as a standard for quantification or calibration in ELISA assays. This practice is widely accepted and validated in scientific protocols for measuring IL-6 concentrations in biological samples.

Supporting details:

• Assay Calibration: ELISA kits for human IL-6 are routinely calibrated using recombinant human IL-6, including those referenced to the WHO/NIBSC international standard (code 89/548). This ensures traceability and comparability of results across laboratories.

• Standard Curve Generation: Recombinant IL-6 is serially diluted to generate a standard curve, which is then used to quantify IL-6 concentrations in unknown samples. Typical concentration ranges for standard curves span from high picogram to low nanogram per milliliter levels, depending on assay sensitivity.

• Specificity and Parallelism: ELISA kits are validated to recognize both recombinant and endogenous (natural) human IL-6, with parallelism tests confirming that recombinant IL-6 behaves equivalently to native IL-6 in the assay matrix. This ensures accurate quantification regardless of the IL-6 source.

• Best Practices:

  • Use the recombinant IL-6 standard provided or recommended for your specific ELISA kit, as antibody specificity and calibration may vary.
  • Prepare the standard according to the manufacturer’s instructions, ensuring proper dilution and inclusion of carrier proteins if required to maintain stability and activity.
  • Always run a fresh standard curve with each assay to account for potential variability in reagent performance.

• Conversion to International Units: If your assay is calibrated against the WHO/NIBSC standard, conversion factors may be provided to express results in standardized units.

Summary of scientific application:
Recombinant human IL-6 is a validated and reliable standard for ELISA quantification, provided it is properly prepared and matched to the assay system. This enables accurate measurement of IL-6 in research and clinical samples.

Recombinant Human IL-6 has been validated for a wide range of applications in published research, primarily in cell culture, differentiation studies, functional assays, and bioassays. It is extensively used to study immune regulation, hematopoiesis, inflammation, and disease modeling.

Key validated applications include:

• Cell Culture and Differentiation:

  • Promotes differentiation of B cells and T cells (especially Th17 subset).
  • Stimulates proliferation of hematopoietic progenitor cells and hybridoma cells.
  • Used for in vitro differentiation of Th17 cells and induction of colony formation from hematopoietic progenitors.

• Functional Assays and Bioactivity Testing:

  • Assessed for its ability to stimulate cell proliferation (e.g., mouse plasmacytoma cell lines).
  • Used in bioassays to evaluate cytokine activity and cellular responses.

• Disease Modeling and Mechanistic Studies:

  • Investigated in models of inflammatory diseases (e.g., rheumatoid arthritis, sepsis, juvenile idiopathic arthritis, Castleman disease).
  • Used to study cancer biology, including effects on myeloma cells and tumor microenvironment.
  • Applied in research on cytokine release syndrome (CRS), especially in the context of CAR T-cell therapies.

• Immunology and Hematopoiesis:

  • Explored for its role in immune response regulation, acute phase protein generation, and hematopoiesis.
  • Used to replace feeder cells in hybridoma production.

• Antibody Production and Detection:

  • Utilized as a standard or positive control in western blotting and antibody validation assays.
  • Used for the production of IL-6-specific antibodies.

• Stem Cell and Dendritic Cell Research:

  • Applied in protocols for expansion and differentiation of airway epithelial cells and dendritic cells.

• Inflammation and Metabolic Disease Research:

  • Studied in models of chronic inflammation, obesity, insulin resistance, and atherosclerosis.

These applications are supported by numerous published studies and product validations, demonstrating the versatility of recombinant human IL-6 in basic and translational research across immunology, oncology, cell biology, and disease modeling.

To reconstitute and prepare Recombinant Human IL-6 protein for cell culture experiments, dissolve the lyophilized protein in a sterile buffer—commonly sterile PBS (pH 7.2–7.4) or sterile double-distilled water—to a concentration of 0.1–0.2 mg/mL, optionally including 0.1%–1% carrier protein such as human or bovine serum albumin (HSA/BSA) to enhance stability and prevent adsorption to surfaces.

Step-by-step protocol:

• Centrifuge the vial briefly before opening to ensure all lyophilized material is at the bottom.
• Add sterile buffer (e.g., PBS or double-distilled water) to achieve the desired concentration (typically 0.1–0.2 mg/mL).
• If long-term storage or repeated freeze-thaw is anticipated, add 0.1%–1% endotoxin-free HSA or BSA as a carrier protein.
• Gently mix by swirling or tapping; do not vortex, as this may denature the protein.
• Allow the protein to fully dissolve; this may take several minutes at room temperature.
• Aliquot the solution to avoid repeated freeze-thaw cycles, which can degrade the protein.
• Store aliquots at –20°C or –80°C under sterile conditions.

Working solution preparation:

• Dilute the reconstituted stock to the desired working concentration in cell culture medium immediately before use.
• Typical working concentrations for cell stimulation range from 0.1–10 ng/mL, depending on cell type and experimental design.

Additional notes:

• Avoid repeated freeze-thaw cycles, as these can reduce protein activity.
• If the protein appears as a film, ensure thorough but gentle mixing to fully dissolve.
• Always use sterile technique to prevent contamination.

This protocol ensures optimal solubility, stability, and bioactivity of recombinant human IL-6 for cell culture applications.