Recombinant Rat Interferon gamma (IFNγ)

Recombinant Rat Interferon gamma (IFNγ) is used in research applications to precisely model and manipulate rat immune responses, particularly for studies involving immunology, infection, inflammation, and cell signaling. It provides a standardized, speciesspecific reagent for in vitro and in vivo experiments, ensuring reproducibility and biological relevance in ratbased systems.

Key scientific reasons to use recombinant rat IFNγ:

• Species specificity: Rat IFNγ is highly speciesspecific; using recombinant rat IFNγ ensures accurate activation of rat IFNγ receptors and downstream signaling pathways, which is critical since human or mouse IFNγ does not reliably crossreact with rat cells.
• Immunological modeling: IFNγ is a central cytokine in both innate and adaptive immunity. It is essential for Th1 immune responses, regulates T cell differentiation and activation, and is required for the killing of intracellular pathogens by activating macrophages and enhancing antigen presentation.
• Functional assays: Recombinant rat IFNγ is widely used in:
  • Bioassays to stimulate or modulate immune cells (e.g., macrophages, NK cells, T cells) in vitro.
  • ELISA standards for quantifying IFNγ or related immune responses.
  • In vivo studies to model immunemediated diseases, inflammation, or tumor immunity in rats.
• Mechanistic studies: It enables investigation of IFNγdependent pathways, such as JAK/STAT signaling, MHC class I/II upregulation, and cytokine crosstalk, under controlled conditions.
• Reproducibility and purity: Recombinant proteins are produced under defined conditions, offering high purity, low endotoxin levels, and batchtobatch consistency, which are critical for reliable experimental outcomes.

Common research applications include:

• Studying hostpathogen interactions and immune defense mechanisms.
• Modeling autoimmune diseases, inflammation, and neuroimmunology in rats.
• Investigating tumor immunology and the effects of IFNγ on tumor cells and the tumor microenvironment.
• Exploring cytokine signaling and gene regulation in rat immune cells.

In summary, recombinant rat IFNγ is an essential tool for dissecting immune mechanisms in rat models, providing specificity, reproducibility, and functional relevance for a wide range of immunological and biomedical research applications.

Yes, recombinant rat Interferon gamma (IFNγ) can be used as a standard for quantification or calibration in ELISA assays, provided it is of high purity and its concentration is accurately known. This is a common and accepted practice in quantitative ELISA protocols for cytokines such as IFNγ.

Supporting details:

• ELISA kits for rat IFNγ routinely use recombinant rat IFNγ as the standard to generate calibration curves for quantification. These standards are serially diluted to create a standard curve, against which sample concentrations are interpolated.
• Assay specificity and validation: Commercial ELISA kits specify that their antibodies and protocols are validated for both natural and recombinant rat IFNγ, and that recombinant IFNγ is suitable for use as a standard. Doseresponse curves for recombinant and natural IFNγ are reported to be parallel, indicating comparable recognition by the assay antibodies.
• Purity and quantification: The recombinant IFNγ used as a standard should be of high purity (typically >95%) and its concentration should be accurately determined, ideally by absorbance at 280 nm using a known extinction coefficient or by amino acid analysis. Carrierfree preparations are preferred for standard curve preparation to avoid interference from stabilizing proteins.
• Matrix effects: When using recombinant IFNγ as a standard, it is important to dilute it in the same buffer or matrix as your samples to minimize matrix effects and ensure accurate quantification.
• Documentation: Some suppliers specifically offer recombinant rat IFNγ as an "ELISA standard," indicating its intended use for calibration in quantitative immunoassays.

Best practices:

• Prepare a serial dilution of the recombinant IFNγ in the same diluent as your samples.
• Include the standard curve in every assay run.
• Confirm that the standard curve covers the expected concentration range of your samples.
• Ensure the recombinant IFNγ is stored and handled according to manufacturer recommendations to maintain stability and activity.

Limitations:

• If your ELISA kit is designed for a specific form or tag of IFNγ, verify compatibility with your recombinant standard.
• Always check the kit manual for any specific requirements or recommendations regarding standards.

In summary: Using recombinant rat IFNγ as a standard is standard practice for ELISA quantification, provided the protein is pure, accurately quantified, and compatible with your assay system.

Recombinant Rat Interferon gamma (IFNγ) has been validated for several key applications in published research, primarily in bioassays using whole cells and in vivo studies in rat models.

Validated Applications in Published Research:

• Bioassays (in vitro):

  • Used to stimulate rat immune cells (e.g., T cells, NK cells, macrophages) to study cytokine signaling, immune activation, and downstream effects such as antigen presentation, immunoglobulin class switching, and macrophage activation.
  • Applied in studies investigating apoptosis in pancreatic betacells, regulation of NOX1 expression, and protection against cytokineinduced necrosis in islets.
  • Utilized to model inflammatory responses, including the role of IFNγ in neuropathic pain, wound healing, and autoimmune encephalomyelitis.
  • Employed in research on hostpathogen interactions, such as the response of rat macrophages to Toxoplasma gondii and the antiviral effects against SARSCoV2.

• In Vivo Studies:

  • Administered to rats to assess immunomodulatory effects, including enhancement of immune cell infiltration in tumors, modulation of inflammatory responses, and protection against viral infections.
  • Used in models of glioma to study tumor invasion and immune cell recruitment following intratumoral infusion of IFNγ.
  • Investigated for its role in wound healing and tissue protection in chemotherapyinduced alopecia and corneal injury models.

Additional Context:

• IFNγ is a pleiotropic cytokine with antiviral, antiproliferative, apoptotic, and immunomodulatory properties.
• It is frequently used to activate Th1 responses, upregulate MHC molecules, and study mechanisms of immune regulation and inflammation in rat cells and tissues.
• Recombinant rat IFNγ is typically validated for use in cell culture bioactivity assays and animal models, with published protocols supporting its reliability in these systems.

Summary Table of Validated Applications

Key References:

• Bioassay and in vivo validation:
• Mechanistic studies:

If you require specific protocols or details for a particular application, please specify the research context or experimental system.

To reconstitute and prepare Recombinant Rat Interferon gamma (IFNγ) for cell culture experiments, dissolve the lyophilized protein in sterile water or sterile PBS containing at least 0.1% carrier protein (such as bovine serum albumin, BSA) to a concentration of 0.1–0.5 mg/mL.

Essential steps and best practices:

• Centrifuge the vial briefly before opening to collect the lyophilized powder at the bottom.
• Add sterile water or PBS (pH 7.2–7.4) with 0.1% BSA to achieve the desired stock concentration (commonly 0.1 mg/mL or 100 μg/mL).
• Gently mix by pipetting up and down or by gentle inversion. Do not vortex, as this may denature the protein.
• Allow several minutes for complete dissolution. If undissolved material remains, centrifuge and use only the clear supernatant.
• Aliquot the stock solution to avoid repeated freezethaw cycles. Store aliquots at 80°C for longterm storage, or at 4°C for shortterm use (up to one week).
• Dilute the stock solution into cell culture medium immediately before use to achieve the desired working concentration for your experiment.

Additional recommendations:

• Always use sterile, endotoxinfree reagents and tubes to prevent contamination and unwanted immune activation.
• If the protein is supplied without carrier protein, adding BSA or human serum albumin (0.1%) during reconstitution helps stabilize the cytokine and prevents loss due to adsorption to tube walls.
• For sensitive cell types, confirm the absence of preservatives or additives that may affect cell viability.
• Check the manufacturer’s certificate of analysis for recommended reconstitution buffer and concentration, as these may vary depending on formulation.

Example protocol:

1. Briefly centrifuge the vial.2. Add sterile PBS (pH 7.2–7.4) with 0.1% BSA to achieve 100 μg/mL.3. Gently pipette to dissolve. Do not vortex.4. Wait 5–10 minutes for complete dissolution.5. Centrifuge if precipitate remains; use only the supernatant.6. Aliquot and store at 80°C.7. Dilute into cell culture medium for experiments.

Note: Always consult the specific product datasheet for any unique instructions regarding reconstitution and storage.