Recombinant Human IGF-I (Previously QED Part No.: 20802P)

Recombinant Human IGF-I is widely used in research due to its potent ability to stimulate cell proliferation, differentiation, tissue regeneration, and metabolic regulation, making it a valuable tool for studies in cell biology, tissue engineering, metabolism, and disease modeling. Its recombinant production ensures high purity, batch-to-batch consistency, and eliminates the risks associated with animal-derived proteins.

Key scientific reasons to use recombinant human IGF-I in research applications include:

• Cell Growth and Differentiation: IGF-I is a critical growth factor that promotes the proliferation and differentiation of various cell types, including muscle, bone, and neural cells. This makes it essential for studies on development, regeneration, and disease.
• Tissue Repair and Regeneration: IGF-I plays a central role in tissue repair, particularly in muscle and bone, and is used to enhance regeneration in tissue engineering and wound healing models.
• Metabolic Regulation: IGF-I regulates glucose metabolism and improves insulin sensitivity, making it relevant for metabolic research, including diabetes and obesity studies.
• Neuroprotection: IGF-I has demonstrated neuroprotective effects and is used in research on neurodegenerative diseases and neural regeneration.
• Drug Discovery and Disease Modeling: Recombinant IGF-I is used as a target or tool in drug screening, especially for conditions related to aging, metabolic disorders, and neuromuscular diseases.
• Immunology and Hematopoiesis: IGF-I, often in combination with other cytokines, stimulates differentiation and proliferation of hematopoietic and immune cells, supporting research in immunology and stem cell biology.

Advantages of recombinant production:

• High Purity and Safety: Recombinant IGF-I is produced in controlled systems (e.g., E. coli), ensuring high purity, low endotoxin levels, and eliminating the risk of animal-derived contaminants.
• Batch Consistency: Recombinant technology provides reproducible results across experiments, which is critical for scientific rigor.
• Versatility: The protein is supplied in formats suitable for a wide range of applications, including cell culture, bioassays, and in vivo studies.

Summary of applications:

• Cell culture supplementation to promote growth and differentiation.
• Tissue engineering and regenerative medicine.
• Metabolic and endocrine research.
• Neurobiology and neuroprotection studies.
• Drug screening and disease modeling.

In summary, recombinant human IGF-I is a versatile, well-characterized growth factor that supports a broad spectrum of research applications due to its biological activity, safety, and consistency.

Yes, recombinant human IGF-I can be used as a standard for quantification and calibration in ELISA assays. This is a well-established practice in IGF-I measurement protocols.

Standard Preparation and Calibration

Recombinant human IGF-I expressed in E. coli serves as the primary calibration standard in commercial IGF-I ELISA kits. The standards are typically supplied as lyophilized preparations that require reconstitution and are available in defined concentration ranges. For example, standard preparations commonly span concentrations from 1 to 50 ng/mL, with intermediate calibration points at 1, 5, 15, 30, and 50 ng/mL.

Performance Characteristics

When using recombinant IGF-I as a standard, you can expect:

Accuracy and Recovery: Recombinant IGF-I standards demonstrate excellent recovery rates, typically ranging from 88.6% to 99.3% when validated against international reference standards. This high recovery ensures that your calibration curve accurately reflects true IGF-I concentrations.

Assay Range: The use of recombinant standards enables a broad dynamic range. Typical ELISA assays using recombinant IGF-I standards achieve measurement ranges from approximately 0.09 ng/mL to 1050 ng/mL, with the ability to adjust this range through sample dilution.

Precision: Intra-assay and inter-assay coefficients of variation typically fall between 4-7%, demonstrating reliable and reproducible calibration.

Important Considerations

The recombinant IGF-I standard should correspond to the full-length human IGF-I protein sequence (amino acids 49-118 of the mature protein). When establishing your calibration curve, ensure the standard is reconstituted according to manufacturer specifications and stored appropriately to maintain stability. Additionally, if comparing results to international standards, note that conversion factors may apply—for instance, a factor of 1.075 may be necessary to align with WHO International Reference Standard preparations.

Recombinant Human IGF-I (Previously QED Part No.: 20802P) has been validated for several applications in published research, primarily focusing on its biological activity and use in cellular and developmental studies. Key applications include:

• Cell Proliferation Assays: IGF-I is widely used to stimulate the proliferation of various cell types, including muscle, bone, cartilage, and epithelial cells. Its mitogenic activity has been demonstrated in assays using cell lines such as MCF-7 human epithelial cells, with reported ED50 values in the range of 1.3–6.5 ng/mL.

• Functional Assays: Recombinant IGF-I is employed in functional assays to study its effects on cell growth, differentiation, and survival. These assays are relevant for understanding developmental processes, tissue regeneration, and disease mechanisms.

• ELISA (Enzyme-Linked Immunosorbent Assay): IGF-I is used as a standard or analyte in ELISA protocols to quantify IGF-I levels in biological samples or to validate antibody specificity.

• Cell Culture: IGF-I is added to cell culture media to support the growth and maintenance of various cell types, especially in studies requiring defined or serum-free conditions.

• Research on Growth and Development: IGF-I is used in studies investigating embryonic development, organogenesis, and the regulation of growth hormone action.

• Therapeutic Research: IGF-I has been studied in the context of treating growth disorders, such as severe primary IGF-I deficiency and growth hormone insensitivity, as well as in conditions like ALS (amyotrophic lateral sclerosis) and hyperinsulinism.

These applications are supported by published research and product documentation, highlighting the versatility and importance of recombinant human IGF-I in both basic and applied scientific studies.

To reconstitute and prepare Recombinant Human IGF-I (previously QED Part No.: 20802P) for cell culture experiments, follow these steps:

• Briefly centrifuge the vial before opening to ensure all lyophilized protein is at the bottom.
• Add sterile water (preferably 18 MΩ-cm resistance) to achieve a concentration of at least 100 µg/mL (0.1 mg/mL). Some protocols recommend concentrations up to 1 mg/mL.
• Do not vortex; gently swirl or tap the vial to dissolve the protein.
• If the protein appears as a film, ensure gentle mixing until fully dissolved.
• For improved stability and to minimize adsorption, you may reconstitute in sterile PBS (pH 7.4) containing 0.1% endotoxin-free recombinant human serum albumin (HSA) or bovine serum albumin (BSA), especially if you plan to store aliquots or use low concentrations.
• After reconstitution, store the solution at 2–8°C for up to 1 week. For longer-term storage, aliquot and freeze at –20°C to –80°C.
• Avoid repeated freeze-thaw cycles to preserve protein activity.

Dilution for cell culture:

• Dilute the stock solution into your cell culture medium immediately before use. Final working concentrations typically range from 1–100 ng/mL, depending on your experimental design and cell type.

Summary of best practices:

• Use sterile technique throughout.
• Prepare aliquots to avoid repeated freeze-thaw.
• Include carrier protein (HSA/BSA) for stability if needed.
• Confirm protein is fully dissolved before use.

These steps ensure optimal solubility, stability, and bioactivity of recombinant IGF-I for cell culture applications.