Recombinant Human FGF R2α (IIIb)

Recombinant Human FGF R2α (IIIb) is a valuable tool in research applications focused on cell signaling, tissue regeneration, cancer biology, and developmental biology due to its role as a high-affinity receptor for fibroblast growth factors (FGFs), especially FGF-2.

FGF R2α (IIIb) is a splice variant of the fibroblast growth factor receptor 2 (FGFR2), predominantly expressed in epithelial tissues. Its interaction with FGFs, particularly FGF-2, mediates critical biological processes:

• Cell Proliferation and Differentiation: FGFR2α (IIIb) activation by FGF-2 stimulates proliferation, migration, and differentiation in various cell types, making it essential for studies on epithelial cell biology, wound healing, and tissue engineering.
• Tissue Regeneration and Repair: The FGF/FGFR2α (IIIb) axis is implicated in promoting angiogenesis, bone formation, and tissue repair, which is relevant for regenerative medicine and studies on chronic wounds or bone defects.
• Cancer and Developmental Biology: Aberrant FGFR2α (IIIb) signaling is associated with tumorigenesis and developmental disorders. Recombinant FGFR2α (IIIb) enables mechanistic studies and drug screening for FGFR-targeted therapies.
• Receptor-Ligand Binding Assays: Recombinant FGFR2α (IIIb) is used to characterize FGF ligand specificity, binding kinetics, and downstream signaling pathways, facilitating the development of FGFR inhibitors or agonists.

Technical Advantages:

• Batch-to-batch consistency and purity: Recombinant proteins offer superior reproducibility and reduced variability compared to native or tissue-derived proteins, which is critical for quantitative and mechanistic studies.
• Defined molecular structure: Recombinant FGFR2α (IIIb) allows for precise control over experimental conditions, including receptor isoform, post-translational modifications, and fusion tags for detection or purification.

Typical Applications:

• Cell-based assays to study FGF signaling and cellular responses.
• In vitro binding studies to screen for FGFR2α (IIIb) ligands or inhibitors.
• Tissue engineering and organoid culture systems requiring defined growth factor-receptor interactions.
• Mechanistic studies of epithelial-mesenchymal interactions in development and disease.

In summary, using recombinant human FGF R2α (IIIb) in research provides a reliable, well-characterized reagent for dissecting FGF signaling pathways, modeling tissue regeneration, and developing targeted therapeutics.

Suitability as an ELISA Standard

The Recombinant Human FGF R2α (IIIb) is not appropriate for use as a standard or calibrator in ELISA assays designed to quantify FGF ligands. This protein serves a fundamentally different role in FGF biology than the ligands typically measured in such assays.

Key Distinctions

Protein Identity and Function

FGF R2α (IIIb) is a receptor protein, specifically the extracellular domain of fibroblast growth factor receptor 2 with the IIIb isoform splice variant. In contrast, ELISA assays for FGF quantification measure ligand proteins such as FGF-2 (basic FGF), FGF-19, FGF-20, or FGF-21. These are fundamentally different molecules with distinct biological roles—receptors bind ligands rather than serving as interchangeable standards for ligand measurement.

Appropriate Standard Selection

For ELISA calibration, you should use recombinant proteins that match the analyte you are measuring. For example, if quantifying human FGF-2, the standard should be recombinant human FGF-2 expressed in the same system and characterized for the same assay format. The standard must demonstrate parallel dose-response curves with natural protein and be validated for the specific assay platform.

Potential Alternative Applications

While FGF R2α (IIIb) cannot serve as a ligand quantification standard, it may have utility in other applications:

• Receptor-ligand binding assays where you measure FGF ligand binding to immobilized receptor
• Competitive inhibition assays evaluating ligand-receptor interactions
• Functional assays assessing receptor activation or signaling

For these applications, the protein's high purity (>90% by SDS-PAGE) and low endotoxin levels (<1.0 EU/µg) make it suitable for research use.

Recommendation: Select a recombinant FGF ligand standard that matches your specific analyte of interest and has been validated for your particular ELISA platform.

Recombinant Human FGF R2α (IIIb) has been validated in published research primarily for applications involving cell signaling studies, receptor-ligand binding assays, and functional cell-based assays. These applications leverage its role as a key receptor for fibroblast growth factors, particularly in the context of epithelial cell biology and growth factor signaling.

Validated Applications in Published Research:

• Cell Signaling and Receptor-Ligand Binding Assays:
  Recombinant Human FGF R2α (IIIb) is commonly used to study the interaction between FGF ligands and their receptors, especially in assays that measure binding specificity and affinity. It is often employed in ELISA-based assays to confirm ligand-receptor interactions and to screen for cross-reactivity with other FGF receptors.

• Functional Cell-Based Assays:
  The protein is used in cell proliferation and differentiation assays to investigate the biological effects of FGF signaling through the IIIb isoform. These assays typically involve epithelial cell lines, as FGFR2α (IIIb) is predominantly expressed in epithelial tissues and mediates responses to FGF ligands such as FGF7 and FGF10.

• Protein Characterization and Biochemical Analysis:
  Recombinant FGFR2α (IIIb) is validated for use in SDS-PAGE and Western blotting to confirm molecular weight, purity, and integrity. It is also used in studies requiring the recombinant receptor for structural or biochemical characterization.

Additional Context:

• No Cross-Reactivity in ELISA:
  Published antibody validation data indicate that ELISA assays using FGFR2α (IIIb) show no cross-reactivity with other FGF receptor isoforms, supporting its specificity for receptor-ligand studies.

• Expression and Purification:
  The recombinant protein is typically expressed in mammalian systems (e.g., HEK293 cells) and purified for use in research applications, ensuring proper folding and post-translational modifications relevant for functional studies.

• Storage and Stability:
  The protein is stable in lyophilized form and suitable for long-term storage, which is important for reproducibility in experimental protocols.

Summary Table:

If you require protocols or more specific experimental details for any of these applications, please specify the context or research focus.

To reconstitute and prepare Recombinant Human FGF R2α (IIIb) protein for cell culture experiments, follow these general best practices based on available protocols and manufacturer recommendations:

Reconstitution

1. Centrifuge the Vial: Before opening, briefly centrifuge the lyophilized protein vial in a microcentrifuge (e.g., 20–30 seconds) to ensure all powder is at the bottom.

2. Reconstitution Buffer: Reconstitute the lyophilized protein in sterile, cold PBS (phosphate-buffered saline, pH 7.2–7.4) or a buffer recommended by the manufacturer. Avoid using distilled water alone, as it may reduce stability.

3. Concentration: Reconstitute to a concentration recommended by the manufacturer (often 100 µg/mL or as specified on the product datasheet). Do not vortex or pipette vigorously; instead, gently swirl or let the vial sit for a few minutes to dissolve.

4. Aliquoting: After reconstitution, aliquot the solution into small volumes to minimize freeze-thaw cycles, which can degrade the protein.

Preparation for Cell Culture

1. Storage: Store aliquots at ≤ –20°C for long-term storage. For short-term use, aliquots can be kept at 2–8°C for up to one month.

2. Further Dilution: For cell culture, dilute the reconstituted protein in culture medium or a buffer containing a carrier protein (e.g., 0.1–0.5% BSA) to enhance stability and prevent adsorption to surfaces.

3. Avoid Repeated Freeze-Thaw Cycles: Thaw aliquots on ice or at 4°C just before use. Discard any unused portion after thawing.

Additional Notes

• Carrier Protein: Adding BSA (0.1–0.5%) to the reconstitution or dilution buffer can help stabilize the protein and maintain activity.
• Sterility: Ensure all steps are performed under sterile conditions if the protein will be used in cell culture.
• Manufacturer’s Instructions: Always refer to the specific product datasheet for lot-specific instructions, as formulations and recommendations may vary.

Example Protocol

1. Centrifuge vial (20–30 sec).
2. Reconstitute with sterile PBS to 100 µg/mL.
3. Gently mix; do not vortex.
4. Aliquot and store at ≤ –20°C.
5. For cell culture, dilute in medium with 0.1% BSA to desired working concentration.

This approach ensures optimal protein stability and activity for cell culture experiments.