Recombinant Human FGF-Basic (154 aa)

Recombinant Human FGF-Basic (154 aa), also known as FGF-2 or bFGF, is widely used in research due to its potent mitogenic, angiogenic, and cell survival activities, making it essential for applications involving cell proliferation, stem cell maintenance, tissue engineering, and regenerative medicine.

Key reasons to use Recombinant Human FGF-Basic (154 aa) in research applications:

• Stem Cell Culture and Maintenance: FGF-basic is a critical component for maintaining embryonic stem cells and induced pluripotent stem cells (iPSCs) in an undifferentiated, proliferative state, preventing spontaneous differentiation during culture. This is vital for experiments requiring pluripotent or multipotent stem cells.

• Cell Proliferation and Survival: It induces robust proliferation in a variety of cell types, including fibroblasts, neuronal cells, endothelial cells, and more. The protein is highly active in bioassays, with effective concentrations (ED50) as low as 0.02–1.0 ng/mL for NIH/3T3 cell proliferation.

• Angiogenesis and Tissue Repair: FGF-basic (154 aa) is a potent angiogenic factor, promoting the formation of new blood vessels, which is crucial for studies in wound healing, tissue regeneration, and cancer biology.

• Developmental Biology: It plays a key role in embryonic development, influencing processes such as cell differentiation, migration, and organogenesis.

• Broad Biological Activity: FGF-basic (154 aa) interacts with multiple FGF receptors (FGFR1–4) and requires heparan sulfate proteoglycans for full activity, enabling it to affect a wide range of physiological and pathological processes, including inflammation and tumor growth.

• Defined, Recombinant Source: Using a recombinant, animal-free FGF-basic (154 aa) ensures batch-to-batch consistency, reduces variability, and minimizes the risk of contamination from animal-derived components, which is especially important for clinical and translational research.

• Versatility in Applications: It is used in protocols for neural stem cell expansion, differentiation assays, organoid culture, and as a supplement in serum-free media for various primary and immortalized cell types.

In summary, Recombinant Human FGF-Basic (154 aa) is a versatile, high-purity growth factor that supports a wide range of cell culture and regenerative research applications, particularly where robust cell proliferation, maintenance of stemness, or angiogenic stimulation are required.

Yes, recombinant human FGF-Basic (154 aa) can be used as a standard for quantification and calibration in ELISA assays, though there are important considerations regarding product designation and intended use.

Appropriate Use as ELISA Standards

Recombinant human FGF-Basic (154 aa) proteins specifically formulated and designated as ELISA standards are suitable for this application. These standards are typically supplied at defined concentrations and have been validated for use in sandwich ELISA formats to quantify FGF-Basic in various sample types including serum, plasma, and cell culture supernatants.

Critical Distinction: Bioassay vs. ELISA-Grade Products

A crucial distinction exists between different formulations of recombinant FGF-Basic. ELISA standard recombinant proteins are not recommended for bioassay usage, as they are not tested for cell proliferation applications. Conversely, bioassay-grade products designated for functional assays should not be used interchangeably as ELISA standards without proper validation.

Product Specifications for ELISA Use

When selecting recombinant FGF-Basic for ELISA standardization, verify the following characteristics:

Purity and Quality: The protein should demonstrate purity greater than 95% as determined by SDS-PAGE analysis. Endotoxin levels should be less than 0.1 EU/µg as measured by kinetic LAL methods.

Formulation Considerations: Products are available in two formulations—with carrier protein (typically bovine serum albumin) or carrier-free. For ELISA applications, either formulation can be used, though carrier-containing versions may offer enhanced stability during storage and handling.

Molecular Characteristics: The 154 amino acid recombinant protein has a predicted molecular mass of approximately 17.2 kDa and migrates at approximately 18 kDa under reducing conditions on SDS-PAGE.

Practical Application Guidance

When using recombinant FGF-Basic as an ELISA standard, prepare serial dilutions in appropriate buffer systems. Typical dilution ranges for ELISA applications span from 0.4 ng/well to higher concentrations depending on your assay sensitivity requirements. The protein should be reconstituted according to manufacturer specifications, typically in buffered solutions such as Tris-buffered saline or phosphate-buffered saline at pH 7.2-7.6.

Ensure that the product you select is explicitly designated for ELISA use rather than bioassay applications to guarantee proper validation and performance in your quantification assays.

Recombinant Human FGF-Basic (154 aa) has been validated for a range of applications in published research, primarily as a bioactive supplement in cell culture, stem cell maintenance, tissue engineering, and in vivo models of wound healing and regeneration.

Key validated applications include:

• Cell Proliferation Assays: FGF-basic (154 aa) robustly induces proliferation of NIH/3T3 fibroblasts and other cell types in dose-dependent bioassays, with ED₅₀ values typically in the range of 0.02–1.0 ng/mL. This is a standard validation for growth factor activity.

• Stem Cell Culture and Maintenance: It is a critical supplement for maintaining human embryonic stem cells (hESCs), induced pluripotent stem cells (iPSCs), and mesenchymal stem cells (MSCs) in an undifferentiated, proliferative state. This includes use in feeder-free and defined media systems.

• Differentiation and Reprogramming Protocols: FGF-basic (154 aa) is used to support differentiation of pluripotent stem cells into various lineages (e.g., neural, mesenchymal, chondrogenic, and endothelial cells) and to enhance reprogramming efficiency.

• Tissue Engineering and Organoid Culture: It is validated for promoting growth and maintenance of organoids (e.g., neural, hepatic, and intestinal organoids) and for supporting tissue engineering constructs.

• Wound Healing and Regeneration Models: In vivo studies have shown that topical application of recombinant human FGF-basic accelerates corneal wound healing in animal models without adverse effects. It is also used in studies of tissue repair and regeneration, including cardiac and neural tissues.

• Angiogenesis and Tumor Biology: FGF-basic (154 aa) is widely used in angiogenesis assays and tumor biology research due to its potent mitogenic and angiogenic properties.

• Bioassays for Functional Activity: The protein is routinely validated in bioassays measuring cell proliferation, migration, and survival across a variety of cell types, including fibroblasts, endothelial cells, neural progenitors, and chondrocytes.

• In Vivo Functional Studies: It has been used in animal models to study developmental processes, tissue repair, and disease mechanisms, including models of spinal cord injury, corneal injury, and cardiac repair.

Summary Table: Validated Applications for Recombinant Human FGF-Basic (154 aa)

Additional Notes:

• FGF-basic (154 aa) is functionally validated by its ability to bind FGFR1–4 and heparan sulfate proteoglycans, and to activate downstream signaling (e.g., ERK1/2 phosphorylation).
• It is broadly distributed in human tissues and acts on diverse cell types, including fibroblasts, endothelial cells, neural cells, and chondrocytes.
• For all applications, recombinant FGF-basic (154 aa) is typically used at nanogram-per-milliliter concentrations, and its activity is confirmed by standardized cell proliferation or survival assays.

If you require details on a specific application or protocol, please specify the research context or cell type of interest.

To reconstitute and prepare Recombinant Human FGF-Basic (154 aa) for cell culture experiments, dissolve the lyophilized protein in sterile water or PBS at a concentration of 0.1–1.0 mg/mL. For optimal stability and activity, further dilute the stock solution in an aqueous buffer containing a carrier protein such as 0.1–1% BSA or HSA.

Step-by-step protocol:

1. Preparation:

   • Briefly centrifuge the vial before opening to collect all protein at the bottom.
   • Warm the vial to room temperature before opening to minimize condensation.

2. Reconstitution:

   • Add sterile distilled water or sterile PBS (pH 7.2–7.4) to achieve a final concentration of 0.1–1.0 mg/mL.
   • For enhanced stability, include 0.1–1% carrier protein (e.g., BSA or HSA) in the buffer.
   • Gently swirl or tap the vial to mix; do not vortex or shake vigorously.
   • If the protein appears as a film, ensure gentle mixing until fully dissolved.

3. Aliquoting and Storage:

   • Aliquot the reconstituted solution to avoid repeated freeze/thaw cycles.
   • Store aliquots at 2–8°C for up to one week, or at –20°C to –80°C for longer-term storage (up to 3 months).
   • Avoid repeated freeze/thaw cycles to preserve bioactivity.

4. Working Solution Preparation:

   • Prepare working dilutions in cell culture medium or buffer containing carrier protein.
   • Typical working concentrations for cell culture range from 0.1–10 ng/mL, depending on cell type and experimental requirements.

Additional notes:

• Confirm protein solubility by running a small aliquot on SDS-PAGE if needed.
• For bioassays, ensure the buffer and carrier protein are endotoxin-free to prevent adverse cellular responses.
• FGF-basic is sensitive to handling; gentle mixing and proper storage are critical for maintaining activity.

Summary Table:

This protocol ensures optimal solubility, stability, and bioactivity of recombinant human FGF-basic (154 aa) for cell culture applications.