Recombinant Human SDF-1α

Recombinant Human SDF-1α (CXCL12) is widely used in research because it is a potent chemokine that regulates cell migration, homing, and tissue regeneration, making it essential for studies in stem cell biology, tissue repair, angiogenesis, and immunology.

Key scientific applications and rationale include:

• Stem Cell Migration and Homing: SDF-1α is a primary chemoattractant for stem and progenitor cells, especially those expressing the CXCR4 receptor. It is crucial for experiments investigating stem cell recruitment to sites of injury or tissue damage, such as in cartilage repair, myocardial infarction, or bone marrow homing.

• Tissue Regeneration and Repair: By promoting the migration of reparative cells, SDF-1α enhances tissue regeneration in models of cartilage injury, myocardial infarction, and wound healing. Studies show that recombinant SDF-1α improves integration strength and functional recovery in engineered tissues.

• Angiogenesis: SDF-1α stimulates endothelial cell migration, proliferation, and tube formation, making it valuable for in vitro and in vivo angiogenesis assays. It is used to model vascular regeneration and study mechanisms of neovascularization in ischemic diseases.

• Immunology and Cell Signaling: SDF-1α/CXCR4 signaling is involved in immune cell trafficking, development, and survival. It is used to dissect chemotactic responses and downstream signaling pathways in various immune and progenitor cell types.

• Cancer Research: SDF-1α is implicated in tumor cell migration, metastasis, and the tumor microenvironment, making it relevant for oncology studies focused on cell invasion and resistance mechanisms.

• Standardization and Reproducibility: Recombinant SDF-1α provides a consistent, defined, and species-specific reagent, essential for reproducible results in cell culture, migration, and functional assays.

Typical research applications include:

• Chemotaxis and migration assays
• Stem cell homing and engraftment studies
• In vitro and in vivo angiogenesis models
• Tissue engineering and regenerative medicine protocols
• Functional assays for immune and progenitor cells

Mechanistically, SDF-1α acts primarily through the CXCR4 receptor, activating signaling pathways that regulate cell movement, survival, and tissue integration.

In summary, using recombinant human SDF-1α enables precise control over experimental conditions in studies of cell migration, tissue repair, angiogenesis, and immune responses, supporting a wide range of biomedical research applications.

Yes, recombinant human SDF-1α can be used as a standard for quantification or calibration in ELISA assays, provided it is validated for this purpose and matches the assay’s requirements.

Supporting context and details:

• ELISA kits designed for SDF-1α quantification routinely use recombinant human SDF-1α as the standard for generating calibration curves. These kits demonstrate that recombinant SDF-1α produces standard curves that are parallel to those generated with natural SDF-1α, indicating equivalence for quantification purposes.
• Assay specificity: Most commercial SDF-1α ELISAs are validated to recognize both natural and recombinant forms of human SDF-1α, ensuring that the recombinant protein is suitable as a standard.
• Calibration and quantification: The immunoassays are calibrated against highly purified recombinant human SDF-1α, and results obtained with natural SDF-1α are shown to be linear and parallel to those with the recombinant standard.
• Best practices:
  • Ensure the recombinant SDF-1α you use as a standard is of high purity and its concentration is accurately determined.
  • The recombinant standard should ideally be from the same source or expression system as that used to calibrate the ELISA kit, as minor differences in post-translational modifications or folding can sometimes affect antibody recognition.
  • Always prepare the standard curve in the same matrix and diluent as your samples to minimize matrix effects.
  • If using a recombinant standard outside of a commercial kit, verify that your ELISA antibodies recognize the recombinant form equivalently to the natural protein.

Limitations and considerations:

• Bioactivity vs. immunoreactivity: ELISA quantifies immunoreactive SDF-1α, not necessarily its bioactive form. Some recombinant preparations may differ in bioactivity, but this does not affect their use as ELISA standards as long as the antibody epitopes are preserved.
• Validation: If you are developing your own ELISA or using a non-kit recombinant SDF-1α, you should validate parallelism between your standard curve and endogenous SDF-1α in your sample matrix.

Summary:
Recombinant human SDF-1α is widely accepted and validated as a standard for ELISA quantification, provided it is compatible with your assay’s antibodies and protocol. Always consult your specific ELISA kit documentation for any restrictions or recommendations regarding standard selection.

Recombinant Human SDF-1α (CXCL12) has been validated for a wide range of applications in published research, primarily focusing on cell migration, tissue regeneration, and signaling pathway studies. Key applications include:

• Cell migration and homing assays: SDF-1α is a potent chemoattractant for T lymphocytes, monocytes, CD34+ hematopoietic progenitor cells, and mesenchymal stem cells, both in vitro and in vivo [1, 13, 11].
• Angiogenesis assays: It promotes endothelial cell outgrowth, proliferation, and tube formation in vitro, supporting studies on vascular regeneration and endothelial function [1, 3, 10].
• Adhesion assays: SDF-1α is used to study cell adhesion mechanisms, particularly in the context of immune and stem cell interactions .
• Wound healing and tissue regeneration: SDF-1α accelerates fibroblast migration, wound closure, and tissue regeneration in preclinical models [10, 12].
• Stem cell and progenitor cell studies: It is employed in assays investigating stem cell mobilization, differentiation, and incorporation into ischemic tissues [3, 6, 8].
• Cancer and metastasis research: SDF-1α signaling via CXCR4 is implicated in tumor growth, metastasis, and immune modulation in various cancers [3, 9, 14].
• Neuronal development and migration: SDF-1α is involved in neuronal migration, neural development, and brain inflammation .
• Cardiovascular research: SDF-1α has been evaluated as a biomarker and therapeutic target in myocardial infarction, heart failure, and vascular regeneration [2, 4, 6].
• Bioactivity and signaling pathway analysis: SDF-1α is used in bioassays to assess activation of signaling pathways such as ERK1/2 and PI3K in endothelial and cancer cells .
• Binding and tracer studies: Radiolabeled SDF-1α is used as a tracer in binding assays and radiometric studies .

These applications demonstrate the versatility of recombinant SDF-1α in both basic research and translational studies across immunology, oncology, neuroscience, and regenerative medicine.

To reconstitute and prepare Recombinant Human SDF-1α (CXCL12) for cell culture experiments, follow these best-practice steps:

• Bring the vial to room temperature before opening to prevent condensation.
• Centrifuge the vial briefly to collect all lyophilized material at the bottom.

Reconstitution:

• Add sterile distilled water or PBS to achieve a final concentration of 0.1–1.0 mg/mL (commonly 100 μg/mL is used for stock solutions).
• For enhanced protein stability and to prevent adsorption to plastic, include 0.1–1% carrier protein (such as BSA or HSA) in the buffer.
• Gently pipette the solution down the side of the vial to dissolve the protein. Do not vortex; instead, allow the vial to sit at room temperature for 15–30 minutes with gentle agitation if needed.
• If the protein appears as a film, ensure thorough but gentle mixing to fully dissolve it.

Aliquoting and Storage:

• Once fully dissolved, aliquot the stock solution to avoid repeated freeze-thaw cycles.
• Store aliquots at –20°C or colder for long-term storage; short-term storage (up to one week) can be at 2–8°C.
• If using carrier-free protein, minimize freeze-thaw cycles as this can denature the protein.

Preparation for Cell Culture:

• Before use, dilute the stock solution to the desired working concentration in cell culture medium, ensuring the final concentration of carrier protein does not adversely affect your cells.
• Typical working concentrations for SDF-1α in cell-based assays range from 0.1 to 100 ng/mL, depending on the assay and cell type.

Additional Notes:

• If a precipitate forms after reconstitution, clarify the solution by brief centrifugation before use.
• Avoid using frost-free freezers for storage, as temperature fluctuations can degrade the protein.
• Always consult the specific product datasheet for any manufacturer-specific recommendations, as formulations may vary.

Summary Table:

These steps ensure maximum stability and biological activity of SDF-1α for cell culture applications.