Recombinant Mouse SDF-1β

Recombinant Mouse SDF-1β (CXCL12-β) is used in research applications to study and manipulate cell migration, tissue repair, fibrosis, and stem cell biology due to its potent chemotactic and regenerative properties.

Key scientific reasons to use recombinant mouse SDF-1β include:

• Stem Cell Recruitment and Migration: SDF-1β is a chemokine that binds to the CXCR4 receptor, directing the migration (chemotaxis) of stem and progenitor cells, including mesenchymal stem cells (MSCs) and hematopoietic stem cells, to sites of injury or inflammation. This property is critical for studies on tissue regeneration, wound healing, and stem cell homing.

• Tissue Repair and Regeneration: In vivo studies demonstrate that SDF-1β enhances recruitment of bone marrow-derived cells (BMCs) and supports neovascularization and tissue repair, particularly after ischemic injury such as myocardial infarction. SDF-1β also promotes alveolar epithelial cell proliferation and migration, supporting lung repair in models of pulmonary fibrosis.

• Antifibrotic Effects: Overexpression or administration of SDF-1β in animal models of lung fibrosis reduces collagen deposition, induces apoptosis of myofibroblasts, and improves lung architecture, suggesting a direct antifibrotic mechanism.

• Synergy with Growth Factors in Bone Regeneration: SDF-1β synergizes with bone morphogenetic protein-2 (BMP-2) to enhance bone formation and mineralization in critical-sized bone defect models, making it valuable for bone tissue engineering and regenerative medicine research.

• Angiogenesis and Vascular Biology: SDF-1β promotes angiogenesis by recruiting endothelial progenitor cells and stimulating vascular growth, which is essential for studies on vascular repair and tissue engineering.

• Modeling Disease Mechanisms: Recombinant SDF-1β can be used to dissect the role of the SDF-1/CXCR4 axis in various disease models, including cardiovascular disease, fibrosis, and cancer metastasis.

• In Vitro Cell Migration and Wound Healing Assays: Recombinant SDF-1β is effective in in vitro assays to study cell migration, wound healing, and chemotaxis, providing a controlled system to analyze cellular responses to chemokine gradients.

Technical considerations:

• Recombinant mouse SDF-1β is typically supplied as a non-glycosylated protein of 72 amino acids (~8.5 kDa), suitable for in vitro and in vivo applications.
• It is important to select the β isoform when inter-organ communication or blood-mediated gradients are of interest, as SDF-1β is more stable in the bloodstream compared to the α isoform.

Summary of applications:

• Stem cell homing and tissue regeneration studies
• Fibrosis and antifibrotic mechanism research
• Bone healing and tissue engineering
• Angiogenesis and vascular biology
• In vitro migration and wound healing assays

Using recombinant mouse SDF-1β enables precise, reproducible manipulation of the SDF-1/CXCR4 axis in mouse models and cell-based assays, facilitating mechanistic studies and therapeutic development in regenerative medicine, fibrosis, and immunology.

Recombinant Mouse SDF-1β can be used as a standard for quantification or calibration in ELISA assays, provided the assay is specifically validated for SDF-1β and the recombinant protein matches the native protein in immunoreactivity and sequence.

Key considerations and supporting details:

• Isoform Specificity: SDF-1 (CXCL12) exists in multiple isoforms, notably α and β. ELISA kits are typically isoform-specific, so you must confirm that your assay is designed to detect SDF-1β, not SDF-1α. Using SDF-1β as a standard in an SDF-1α-specific assay may yield inaccurate results due to potential differences in antibody recognition.

• Recombinant Protein as Standard: Many ELISA kits for mouse SDF-1β are calibrated using recombinant SDF-1β as the standard, indicating that recombinant protein is suitable for quantification if it is of high purity and correctly folded. The recombinant standard should be prepared in the same buffer as the kit standard and diluted according to the kit instructions for accurate calibration.

• Validation and Cross-Reactivity: It is essential to ensure that the recombinant SDF-1β is recognized equivalently to the native protein by the antibodies used in your ELISA. Most commercial kits validate their standards for parallelism and recovery, confirming that recombinant and native proteins yield comparable results. However, always consult the kit datasheet or validation report for confirmation.

• Best Practices:

  • Use recombinant SDF-1β of high purity (typically >95%) and low endotoxin levels for standard curve preparation.
  • Prepare serial dilutions in the recommended diluent to match the matrix of your samples.
  • Run the standard curve in parallel with your samples to ensure accurate quantification.
  • Avoid repeated freeze/thaw cycles of the recombinant protein to maintain activity and integrity.

• Limitations: Some ELISA kits explicitly state that they are not recommended for detection or quantification of recombinant proteins due to differences in folding, post-translational modifications, or epitope presentation. Always verify the kit’s documentation for such restrictions.

• Documentation Example: The LEGEND MAX™ Mouse CXCL12 (SDF-1β) ELISA kit uses recombinant SDF-1β as its standard and is validated for quantification in mouse samples. Similarly, other kits specify detection ranges and sensitivities using recombinant standards.

Summary Table: Recombinant SDF-1β as ELISA Standard

If your ELISA kit is validated for SDF-1β and the recombinant protein matches the native sequence and immunoreactivity, you can confidently use recombinant Mouse SDF-1β as a standard for quantification or calibration in your ELISA assays.

Recombinant Mouse SDF-1β (CXCL12β) has been validated in published research for several key applications, primarily in studies of cell migration, tissue repair, fibrosis, and bone regeneration.

Key validated applications include:

• Cell migration and chemotaxis assays: SDF-1β is a potent chemoattractant, validated for inducing migration of CXCR4-expressing cells such as Baf3-hCXCR4 transfectants in a dose-dependent manner. This property is widely used in in vitro chemotaxis and transwell migration assays.

• Wound healing assays: Recombinant SDF-1β has been used in in vitro wound-healing (scratch) assays, where it significantly enhanced wound closure in A549 epithelial cells in a concentration-dependent manner.

• Fibrosis and tissue repair models: SDF-1β overexpression or recombinant protein administration has been validated in vivo for its anti-fibrotic effects, particularly in bleomycin-induced lung fibrosis models. It promotes myofibroblast apoptosis, reduces collagen deposition, and stimulates alveolar epithelial cell proliferation, supporting its role in tissue repair and regeneration.

• Bone regeneration and osteogenesis: SDF-1β has been validated in mouse critical-size calvarial defect models, where it enhances BMP-2-driven osteogenesis and bone healing. Its co-delivery with BMP-2 or TGF-β1 via biopatterned matrices augments bone formation both in vitro and in vivo.

• Myocardial ischemia and cardiac repair: Recombinant SDF-1 (including SDF-1β) administration in mice has been shown to protect against myocardial ischemia, reduce infarct size, and augment bone marrow cell engraftment in ischemic myocardium.

Additional validated uses:

• Recruitment of mesenchymal stem cells (MSCs): SDF-1β is used to enhance recruitment of MSCs to sites of injury, facilitating tissue repair in various organ systems.
• Bioassays for receptor activation: SDF-1β is commonly used in bioassays to activate CXCR4 and study downstream signaling pathways.

Summary Table of Validated Applications

Notes:

• SDF-1β is often chosen over SDF-1α for its greater resistance to proteolytic cleavage, making it advantageous in certain in vivo applications.
• Most studies use recombinant SDF-1β in cell-based assays, animal models, or as a component in engineered tissue scaffolds.

If you require protocols or more technical details for a specific application, please specify the context.

To reconstitute and prepare Recombinant Mouse SDF-1β (CXCL12β) protein for cell culture experiments, follow these steps to ensure protein stability and biological activity:

1. Centrifuge the vial briefly before opening to collect all lyophilized material at the bottom.

2. Reconstitution buffer:

   • Use sterile phosphate-buffered saline (PBS) or sterile distilled water as the solvent.
   • For enhanced stability, especially at low concentrations, add 0.1%–0.5% carrier protein such as bovine serum albumin (BSA) or human serum albumin (HSA) to the buffer. This is particularly important if the protein is carrier-free or will be stored after reconstitution.

3. Concentration:

   • Reconstitute to a final concentration of 0.1–1.0 mg/mL (100–1000 μg/mL) depending on your experimental needs.
   • For example, to achieve 0.1 mg/mL, add 1 mL of buffer to 100 μg of lyophilized protein.

4. Dissolving the protein:

   • Gently pipette the buffer down the side of the vial to dissolve the protein.
   • Do not vortex; instead, gently swirl or invert to mix.
   • Allow the protein to fully dissolve at room temperature for several minutes.

5. Aliquoting and storage:

   • Prepare small aliquots to avoid repeated freeze-thaw cycles, which can degrade the protein.
   • Store aliquots at –20°C or –80°C for long-term storage.
   • For short-term use (up to 1 week), store at 4°C.

6. Working solution:

   • Dilute the reconstituted stock to the desired working concentration in cell culture medium immediately before use.
   • Typical working concentrations for chemotaxis or signaling assays are in the ng/mL range (e.g., 0.3–2.7 ng/mL for functional assays).

Additional notes:

• Always consult the specific product datasheet for any manufacturer-specific recommendations, as formulation and stabilizer content may vary.
• Avoid repeated freeze/thaw cycles to maintain protein activity.
• If using for sensitive cell types or in serum-free conditions, ensure all buffers and reagents are endotoxin-free.

Summary protocol:

1. Briefly centrifuge vial.
2. Add sterile PBS (with 0.1% BSA) to achieve 0.1–1.0 mg/mL.
3. Gently dissolve by pipetting and swirling.
4. Aliquot and store at –20°C or –80°C.
5. Dilute to working concentration in cell culture medium just before use.

These steps will help ensure optimal activity and reproducibility in your cell culture experiments using recombinant mouse SDF-1β.