Recombinant Human TNF sRI

Recombinant Human TNF sRI (soluble TNF receptor I) is used in research applications primarily as a highaffinity antagonist of TNFα, enabling precise modulation and investigation of TNFαmediated signaling pathways, inflammation, and immune responses.

Key scientific reasons to use Recombinant Human TNF sRI:

• Neutralization of TNFα Activity: TNF sRI binds free TNFα with high affinity, preventing its interaction with cellsurface TNF receptors. This allows researchers to inhibit TNFαmediated cytotoxicity, apoptosis, and inflammatory signaling in vitro and in vivo.

• Modeling Antiinflammatory Mechanisms: By blocking TNFα, TNF sRI mimics the natural regulatory mechanism that controls excessive inflammation. This is valuable for studying the pathogenesis of autoimmune and inflammatory diseases, and for evaluating potential therapeutic interventions targeting TNFα.

• Functional Assays and Controls: Recombinant TNF sRI is used in bioassays to confirm the specificity of TNFα effects, serving as a negative control or as a tool to dissect TNFαdependent cellular responses.

• Disease Mechanism Studies: Soluble TNF receptors are found in biological fluids and are implicated in the regulation of immune responses in conditions such as ischemic stroke, cancer, and chronic inflammatory diseases. Recombinant TNF sRI enables mechanistic studies of these processes.

Technical considerations:

• Purity and Activity: Recombinant TNF sRI is typically purified to >95% and validated for biological activity, such as its ability to inhibit TNFαinduced cytotoxicity in cellbased assays.

• Endotoxin Levels: Low endotoxin content (<0.01 EU/µg) is essential for cell culture and in vivo studies to avoid confounding immune activation.

Typical applications include:

• In vitro cell culture experiments to block TNFα signaling.
• Animal models to study the effects of TNFα inhibition.
• ELISA and other immunoassays as a standard or control for TNFα neutralization.

In summary, Recombinant Human TNF sRI is a critical reagent for dissecting TNFα biology, modeling antiinflammatory strategies, and validating therapeutic approaches targeting TNFα in diverse research contexts.

Recombinant Human TNF sRI (soluble TNF receptor I) is generally not suitable as a standard for quantifying TNFα in ELISA assays designed to measure TNFα, unless your assay specifically detects sTNFRI. Standards for ELISA quantification must match the analyte being measured; using sTNFRI as a standard for TNFα quantification would yield inaccurate results.

Key points:

• ELISA standards must be the same molecule as the analyte. For TNFα quantification, the standard should be recombinant human TNFα, not sTNFRI.
• sTNFRI is a soluble receptor, not the cytokine TNFα. It binds TNFα and may be measured in assays designed for soluble receptors, but it is not interchangeable with TNFα for calibration purposes.
• Assay specificity: Most TNFα ELISA kits are validated to detect both natural and recombinant TNFα, and they specifically test for lack of crossreactivity with sTNFRI and other related proteins.
• If your assay is designed to quantify sTNFRI (soluble TNF receptor I), then recombinant human TNF sRI can be used as a standard for calibration. However, for TNFα quantification, use recombinant TNFα as the standard.

Best practice:

• Always use a standard that matches the analyte for accurate quantification.
• Confirm your ELISA’s specificity and validation data to ensure correct standard selection.

Summary Table:

Using the wrong standard will compromise assay accuracy and reliability. Always match your standard to the analyte your ELISA is designed to detect.

Recombinant Human TNF sRI (soluble TNF Receptor I) has been validated in published research primarily for applications involving the inhibition of TNFαmediated cytotoxicity, especially in cellbased bioassays. The most widely cited and validated application is:

• Inhibition of TNFαmediated cytotoxicity in L929 mouse fibrosarcoma cells: This is a standard assay to confirm the biological activity of recombinant human TNF sRI, where its ability to block TNFαinduced cell death is measured in the presence of actinomycin D.

Additional validated and potential applications, based on the broader use of recombinant TNF receptors and related proteins, include:

• Preclinical models of chronic inflammatory diseases: PEGylated forms of recombinant human soluble TNFRI have been validated in rodent models of diseases such as rheumatoid arthritis, demonstrating efficacy in reducing inflammation and disease severity.
• Therapeutic drug development and screening: Recombinant TNF sRI is used to study TNFα signaling pathways, screen for TNFα inhibitors, and evaluate the neutralizing capacity of candidate drugs or antibodies targeting TNFα.
• Pharmacokinetic and bioanalytical assays: While most ELISAbased assays use recombinant TNFα as a capture reagent, soluble TNF receptors can also be used in ligandbinding assays to quantify TNFα or to monitor the pharmacodynamics of antiTNF therapies.

Summary of validated applications in published research:

• Cellbased bioassays for TNFα inhibition (e.g., L929 cytotoxicity assay).
• Preclinical efficacy studies in animal models of inflammation.
• Screening and characterization of antiTNF drugs and biologics.

Key technical note: The L929 cytotoxicity assay remains the gold standard for validating the biological activity of recombinant human TNF sRI, as it directly measures the protein’s ability to neutralize TNFα in a functional context. Other applications, such as in vivo models and drug screening, are supported by the literature on soluble TNF receptors but may require additional validation depending on the specific experimental context.

To reconstitute and prepare Recombinant Human TNF sRI (soluble TNF Receptor I) protein for cell culture experiments, follow these general best practices based on standard protocols for lyophilized recombinant proteins and specific recommendations for TNF receptor proteins:

Reconstitution

1. Centrifuge the vial briefly before opening to ensure all lyophilized powder is at the bottom.
2. Reconstitute with sterile, cold PBS (phosphatebuffered saline) or as specified in the product datasheet. If the product contains BSA as a carrier, reconstitute with PBS containing at least 0.1% human or bovine serum albumin (BSA) to stabilize the protein. For carrierfree versions, sterile PBS alone is sufficient.
3. Recommended concentration: Reconstitute to a concentration of 100 µg/mL (or as specified by the manufacturer). For example, add 100 µL of buffer to a vial containing 10 µg of protein.
4. Gently mix the solution by swirling or inverting the vial. Avoid vigorous shaking to prevent foaming and protein denaturation.
5. Allow the vial to sit at room temperature for 15–30 minutes with gentle agitation to ensure complete dissolution.

Preparation for Cell Culture

1. Aliquot the reconstituted protein into small, singleuse volumes to minimize freezethaw cycles.
2. Store aliquots at ≤ –20°C (preferably –80°C for longterm storage). Use a manual defrost freezer if possible.
3. Avoid repeated freezethaw cycles, as this can reduce protein activity.
4. For cell culture experiments, dilute the reconstituted protein in appropriate cell culture medium immediately before use. Ensure the final concentration of BSA (if used) is compatible with your cell type and experimental conditions.

Additional Notes

• Carrier protein: If the protein is supplied with BSA, it is generally recommended for cell culture applications as it enhances stability. For applications where BSA may interfere (e.g., certain biochemical assays), use a carrierfree version.
• Sterility: Always use sterile techniques when handling the protein to avoid contamination, especially for cell culture.
• Productspecific instructions: Always refer to the product datasheet or Certificate of Analysis (COA) for any specific reconstitution or storage recommendations.

By following these steps, you can ensure optimal activity and stability of Recombinant Human TNF sRI for your cell culture experiments.