Recombinant Rat TNF-α

Recombinant Rat TNFα is widely used in research applications because it is a key cytokine involved in regulating inflammation, immune responses, apoptosis, and cell signaling, making it essential for modeling disease mechanisms and testing therapeutic interventions in ratbased systems.

Key scientific reasons to use recombinant rat TNFα:

• Speciesspecific activity: Using rat TNFα ensures physiological relevance in rat models, as cytokinereceptor interactions can be speciesspecific, affecting experimental outcomes.
• Central role in inflammation and immunity: TNFα is a pleiotropic molecule that orchestrates inflammatory responses, immune cell regulation, and apoptosis, making it crucial for studies on autoimmune diseases, infection, and tissue injury.
• Disease modeling: Recombinant rat TNFα is used to induce or modulate disease states such as rheumatoid arthritis, intervertebral disc degeneration, and neuropathic pain in vivo, allowing for mechanistic studies and drug testing.
• Cellular and molecular assays: It is applied in bioassays to study cytokine signaling, cell death, and immune cell activation in vitro, facilitating the dissection of TNFα pathways and their modulation by drugs or genetic interventions.
• Therapeutic development: Recombinant TNFα is used to screen and validate antiTNF therapies, investigate receptor selectivity, and explore novel drug delivery systems, supporting translational research.
• Standardization and reproducibility: Recombinant proteins provide consistent, defined activity and purity, enabling reproducible results across experiments and laboratories.

Typical applications include:

• Inducing inflammatory responses in cell cultures or animal models.
• Studying cytokinemediated apoptosis and necrosis.
• Investigating TNFα’s role in osteoclastogenesis, metabolic regulation, and tumor biology.
• Testing antiinflammatory or immunomodulatory compounds targeting TNFα signaling.

Best practices:

• Use recombinant rat TNFα for rat cell lines or in vivo rat studies to ensure accurate receptor binding and downstream signaling.
• Validate activity and endotoxin levels to avoid confounding immune responses.
• Optimize dosing and timing based on experimental goals and published protocols.

In summary, recombinant rat TNFα is indispensable for immunology, inflammation, and disease research in rat models, providing speciesspecific, reproducible, and mechanistically relevant insights into TNFα biology and therapeutic targeting.

Yes, recombinant rat TNFα can be used as a standard for quantification or calibration in ELISA assays, provided it is properly validated and matched to your assay system. Recombinant TNFα is widely used as a standard in commercial rat TNFα ELISA kits and in published protocols for quantitative measurement.

Supporting details:

• Specificity and Parallelism: ELISA kits designed for rat TNFα typically recognize both natural and recombinant forms, and doseresponse curves for recombinant TNFα are parallel to those for natural TNFα, indicating suitability for quantification.
• Calibration: Many ELISA kits are calibrated against highly purified recombinant rat TNFα, and the standard curve generated with recombinant protein is used to interpolate sample concentrations.
• Applications: Recombinant rat TNFα is routinely used as an immunoassay standard for building calibration curves in ELISA protocols measuring TNFα in serum, plasma, cell culture supernatant, and tissue lysates.
• Validation: For best practice, ensure the recombinant TNFα standard is validated for your specific ELISA system. Check that the standard curve generated with recombinant TNFα is parallel to curves obtained with natural TNFα in your sample matrix. This confirms that the assay quantifies both forms equivalently.

Best practices:

• Use recombinant TNFα that matches the extracellular domain sequence of native rat TNFα, as this is the immunoreactive portion detected by most ELISA antibodies.
• Prepare serial dilutions of the recombinant standard in the same buffer or diluent used for your samples to minimize matrix effects.
• Always run the standard curve in parallel with your samples for accurate quantification.

Limitations:

• Recombinant standards are for research use only and not for diagnostic procedures.
• Minor differences in glycosylation or folding between recombinant and native TNFα (depending on the expression system) are generally not significant for ELISA quantification, but should be considered if absolute quantification is critical.

Summary Table: Recombinant Rat TNFα as ELISA Standard

In conclusion, recombinant rat TNFα is appropriate for use as a standard in ELISA quantification and calibration, provided it is validated for your assay system and used according to best practices.

Recombinant Rat TNFα has been validated for a range of applications in published research, primarily in the context of inflammation, immune modulation, and cell signaling studies. The most commonly validated applications include:

• In Vivo Studies: Used to induce or modulate inflammatory responses, model disease states (such as rheumatoid arthritis, intervertebral disc degeneration, renal disease, neuropathic pain, and sleep regulation), and assess therapeutic interventions in rat models.
• Bioassays: Employed to measure biological activity, such as cytotoxicity (e.g., using L929 fibroblast cells), cytokine induction, and signaling pathway activation in cultured cells.
• ELISA (EnzymeLinked Immunosorbent Assay): Used as a standard or control for quantifying TNFα levels in biological samples, particularly in infection and inflammation models.
• Immunomodulation and Gene Therapy Research: Utilized in studies investigating the effects of TNFα antagonism or RNA interference (RNAi) strategies for diseases like rheumatoid arthritis, including oral delivery of TNFα shRNA.
• Western Blotting and SDSPAGE: Used as a positive control or standard for protein detection and quantification in biochemical assays.
• Mass Cytometry (CyTOF) and Spatial Biology: Applied in advanced cell profiling and tissue analysis techniques.

Supporting details and examples from published research:

• In Vivo Applications: Recombinant rat TNFα has been used to induce inflammation in models of intervertebral disc degeneration, abdominal aortic aneurysm, renal disease, and neuropathic pain, as well as to study its effects on sleep regulation and neuronal sensitivity.
• Bioassays: Validated for use in cytotoxicity assays (e.g., L929 mouse fibroblast cells), cytokine mRNA induction, and signaling pathway studies in whole cells.
• ELISA: Used as a standard in rat pneumonia and softtissue infection models to quantify TNFα.
• Gene Therapy Research: Studies have used recombinant TNFα and its antagonists to evaluate immunomodulatory effects and safety in rheumatoid arthritis models, including oral delivery of TNFα shRNA.
• Protein Detection: Recombinant rat TNFα is suitable for SDSPAGE and Western blotting as a standard or control protein.

Summary Table of Validated Applications

These applications are supported by multiple peerreviewed studies and product validation data, confirming the utility of recombinant rat TNFα in both basic and translational research contexts.

To reconstitute and prepare Recombinant Rat TNFα protein for cell culture experiments, dissolve the lyophilized protein in sterile buffer at a concentration of at least 100 μg/mL, using sterile PBS or distilled water, and include 0.1% serum albumin if possible to stabilize the protein.

Stepbystep protocol:

• Centrifuge the vial briefly before opening to ensure all lyophilized material is at the bottom.
• Reconstitution buffer: Use sterile PBS or sterile distilled water. For enhanced stability, add at least 0.1% human or bovine serum albumin (BSA).
• Concentration: Do not reconstitute to less than 100 μg/mL. Typical working concentrations for cell culture range from 0.1–1.0 mg/mL for stock solutions.
• Mixing: Gently swirl or invert the vial to dissolve. Avoid vortexing or vigorous pipetting, which can denature the protein.
• Aliquoting: Divide the reconstituted solution into small aliquots in polypropylene tubes to minimize freezethaw cycles.
• Storage: Store aliquots at −20 °C to −70 °C. Avoid repeated freezethaw cycles, as this can reduce bioactivity.
• Dilution for cell culture: Before use, dilute the stock solution into cell culture medium to the desired final concentration. Ensure the medium is compatible with TNFα and does not contain components that may inactivate the cytokine.

Additional notes:

• Always bring the protein to room temperature before use.
• For sensitive applications, filtersterilize the final working solution if necessary.
• The presence of carrier protein (BSA) is recommended for longterm stability, especially at low concentrations.
• Avoid storing reconstituted protein at 2–8 °C for more than 1 month.

Summary Table:

This protocol ensures optimal solubility, stability, and bioactivity of recombinant rat TNFα for cell culture experiments.