Recombinant Human/Mouse/Rat Activin A

Recombinant Human/Mouse/Rat Activin A is widely used in research because it is a multifunctional cytokine that regulates key biological processes, including cell proliferation, differentiation, apoptosis, immune response, and tissue repair. Using the recombinant form ensures high purity, batch-to-batch consistency, and species cross-reactivity, which are critical for reproducible and interpretable experimental results.

Key reasons to use recombinant Activin A in research applications:

• Regulation of Cell Fate: Activin A is a member of the TGF-β superfamily and is essential for controlling cell proliferation, differentiation, and apoptosis in various cell types. It is particularly important in stem cell biology, where it is used to maintain pluripotency in human induced pluripotent stem cells (iPSCs) and to direct differentiation toward endodermal and pancreatic lineages.

• Reproductive and Developmental Biology: Activin A stimulates follicle-stimulating hormone (FSH) secretion and plays a crucial role in reproductive system function and embryonic development.

• Immunology and Inflammation: Activin A modulates immune responses, making it relevant for studying allergy, autoimmunity, inflammation, and cancer immunology. It can influence immune cell behavior and tumor immune evasion, and interfering with its activity is being explored to overcome immunotherapy resistance.

• Wound Healing and Tissue Repair: Activin A is involved in tissue morphogenesis, wound healing, and fibrosis, making it valuable for regenerative medicine and tissue engineering studies.

• Cancer Research: Activin A can promote tumor cell migration and growth, and its signaling is implicated in carcinogenesis. It is both a target and a tool in cancer biology research.

• Consistency and Scalability: Recombinant production allows for large-scale, animal-free, and highly pure protein, overcoming the limitations of isolating Activin A from natural sources. This ensures reproducibility and reduces variability in experimental outcomes.

• Cross-Species Applications: The high sequence identity between human, mouse, and rat Activin A enables use across multiple model systems, facilitating translational research.

• Validated Biological Activity: Recombinant Activin A is tested for specific biological activities (e.g., induction of cytotoxicity in MPC-11 cells, FSH secretion), ensuring functional relevance in assays.

In summary, recombinant Human/Mouse/Rat Activin A is a critical reagent for studies in cell biology, immunology, developmental biology, regenerative medicine, and cancer research due to its well-characterized, reproducible, and versatile biological effects.

Yes, you can use recombinant Human/Mouse/Rat Activin A as a standard for quantification or calibration in your ELISA assays, provided that the recombinant protein is well-characterized, purified, and compatible with your assay system.

Key Points Supporting Use as a Standard:

• Expression and Validation: Recombinant Activin A proteins (including those expressed in CHO, E. coli, HEK293, and insect cells) are commonly used as standards in ELISA assays for human, mouse, and rat samples. These proteins have been validated for use in functional assays, Western blot, ELISA, and immunohistochemistry (Source ).

• Calibration in Commercial ELISA Kits: Many commercial ELISA kits, such as the Human/Mouse/Rat Activin A Quantikine ELISA Kit (DAC00B), are calibrated against highly purified CHO cell-expressed recombinant Activin A. These kits demonstrate that recombinant Activin A accurately quantitates both recombinant and naturally expressed Activin A, with parallel dose-response curves (Sources , , , ).

• Specificity and Linearity: The use of recombinant Activin A as a standard has been shown to yield linear standard curves and accurate quantitation across sample types such as serum, plasma, cell culture supernatants, and saliva. The assay recognizes both natural and recombinant forms of Activin A, with minimal cross-reactivity to related proteins (Sources , , ).

• Best Practices:

  • Ensure the recombinant Activin A standard is purified and free of contaminants.
  • Prepare a dilution series of the standard to generate a calibration curve.
  • Include the standard in each assay run to account for inter-assay variability.
  • Confirm that the standard is compatible with your detection antibodies and assay buffer conditions.

Conclusion:

Recombinant Human/Mouse/Rat Activin A is suitable and widely used as a standard for quantification and calibration in ELISA assays. Always follow the manufacturer’s recommendations for standard preparation and assay conditions to ensure accurate and reproducible results.

Recombinant Human/Mouse/Rat Activin A has been validated for a wide range of applications in published research, including:

• Functional Assays/Bioassays: Used to assess biological activity, such as induction of hemoglobin expression in K562 cells, cytotoxicity in MPC-11 cells, and regulation of cell differentiation and proliferation.
• Western Blot: Detection and quantification of Activin A in various samples.
• ELISA: Quantitative measurement of Activin A levels.
• Immunohistochemistry: Localization of Activin A in tissue sections.
• Stem Cell Differentiation: Promotes definitive endoderm differentiation of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs).
• Cell Culture: Supports cell proliferation, differentiation, and migration in various cell types.
• HPLC: Used for purity analysis and quantification.
• SDS-PAGE: Assessment of protein purity and molecular weight.
• In Vivo Studies: Administration in animal models to study effects on muscle mass, immune responses, and tumor migration.
• Cancer Research: Investigates roles in tumor migration, growth, and immune evasion.
• Immunology: Explored for its adjuvanticity in vaccine development and modulation of immune responses.
• Regenerative Medicine: Utilized in protocols for disease modeling, drug screening, and tissue regeneration.

These applications highlight the versatility and importance of Recombinant Human/Mouse/Rat Activin A in both basic and applied research settings.

To reconstitute and prepare Recombinant Human/Mouse/Rat Activin A protein for cell culture experiments, dissolve the lyophilized protein at a concentration of 100–500 μg/mL in sterile 4 mM HCl. After reconstitution, dilute the protein to your desired working concentration using cell culture medium or buffer containing a carrier protein such as 0.1% human serum albumin (HSA) or bovine serum albumin (BSA) to minimize adsorption and maintain stability.

Step-by-step protocol:

1. Centrifuge the vial briefly before opening to ensure all lyophilized material is at the bottom.
2. Add sterile 4 mM HCl to the vial to achieve a final concentration of 100–500 μg/mL.
3. Gently swirl or tap the vial to mix. Avoid vigorous pipetting or vortexing, which may denature the protein.
4. Allow the protein to fully dissolve (this may take several minutes).
5. Aliquot the reconstituted protein to avoid repeated freeze-thaw cycles.
6. For cell culture use, dilute the stock solution into your culture medium or buffer. Include 0.1% HSA or BSA as a carrier protein to stabilize the protein and prevent loss due to adsorption.
7. Storage after reconstitution:
   • Store at 2–8 °C for up to 1 month.
   • For longer-term storage, aliquot and freeze at –20 °C to –80 °C for up to 3–6 months.
   • Avoid repeated freeze-thaw cycles to preserve activity.

Additional notes:

• If your application is sensitive to animal-derived components, use recombinant HSA as the carrier protein.
• Always refer to the specific Certificate of Analysis (CoA) for your lot for any unique instructions.
• For some products, reconstitution in water or PBS is possible, but 4 mM HCl is generally recommended for optimal solubility and stability of Activin A.

Summary Table:

This protocol ensures maximal solubility, stability, and bioactivity of recombinant Activin A for cell culture applications.