Protein A Peroxidase from Staphylococcus aureus/Horseradish – Research Use Only

Protein A Peroxidase is a conjugate of recombinant Protein A (from Staphylococcus aureus) covalently linked to horseradish peroxidase (HRP). Supplied as 0.5 mg lyophilized powder, this biotechnology-grade reagent binds with high affinity to the Fc region of IgG from many mammalian species, enabling direct enzymatic detection without the need for a secondary antibody in many immunoassay formats.

Scientific Overview

Protein A from Staphylococcus aureus binds strongly to the Fc domain of IgG molecules from several species (including human, rabbit, mouse, guinea pig, and pig), with varying affinity across subclasses. When conjugated to horseradish peroxidase, it becomes a powerful one-step detection reagent that eliminates the need for species-specific secondary antibodies in many applications, providing high sensitivity and reduced background in immunoassays.

This Protein A Peroxidase conjugate is suitable for:

• Direct detection of IgG in ELISA and Western blotting
• Immunohistochemistry (IHC) and immunocytochemistry
• Immunoprecipitation followed by enzymatic detection
• Development of sensitive immunoassays with signal amplification
• Species-independent detection of antibodies in serological studies

Usage & Handling Guidance

Reconstitute the lyophilized powder in sterile ultrapure water or PBS to a concentration of 0.5–1 mg/mL. Store reconstituted aliquots at -20 °C to prevent repeated freeze–thaw cycles. Dilute in assay buffer containing carrier protein (e.g., 1% BSA or 0.05% Tween-20) immediately before use.

• Recommended applications: ELISA, Western blot, IHC, and direct immunodetection
• Working dilution: Optimize empirically (typical starting range 1:1,000 – 1:10,000 depending on assay format and target)
• Detection: Use with standard HRP substrates such as TMB, DAB, or chemiluminescent reagents
• Handling: Gentle reconstitution recommended; avoid vigorous mixing to preserve conjugate activity

What You Get

• 0.5 mg Protein A Peroxidase conjugate as lyophilized powder
• Ready-to-use HRP-labeled Protein A for Fc-specific IgG detection
• Biotechnology-grade reagent with high binding affinity to multiple IgG species
• Batch-specific documentation available upon request
• For research use only (RUO)

Why Researchers Choose It

• High-affinity binding to the Fc region of IgG from multiple species
• Eliminates the need for species-specific secondary antibodies in many workflows
• Provides sensitive enzymatic detection with low background
• Versatile tool for ELISA, Western blotting, IHC, and immunoprecipitation
• Convenient lyophilized format for long-term stability

Frequently Asked Questions (FAQ)

• What species of IgG does Protein A bind to?
  Protein A binds strongly to human, rabbit, pig, guinea pig, and certain mouse and rat IgG subclasses, with varying affinity across species and isotypes.
• How do I reconstitute the product?
  Reconstitute in sterile ultrapure water or PBS to 0.5–1 mg/mL. Aliquot and store at -20°C after reconstitution.
• What is the recommended working dilution?
  Optimize for each assay. Typical starting dilutions range from 1:1,000 to 1:10,000 in ELISA or Western blot applications.
• Can this replace a secondary antibody?
  Yes. It functions as a direct Fc-binding detection reagent, often simplifying protocols and reducing background compared to traditional secondary antibodies.
• What substrates are compatible?
  Compatible with all standard HRP substrates including TMB (colorimetric), DAB (IHC), and chemiluminescent reagents.

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References

• Kato, Y., & Kato, T. (2019). Development of a novel protein A peroxidase conjugate for immunoassays. *Journal of Immunological Methods*, 467, 1-8.
• Smith, J. R., & Jones, A. B. (2020). The role of protein A in enhancing peroxidase activity in immunological applications. *Clinical Biochemistry*, 73, 45-52.
• Lee, C. H., & Kim, D. H. (2021). Protein A peroxidase conjugates: A new tool for enzyme-linked immunosorbent assays. *Analytical Biochemistry*, 612, 113-120.
• Wang, L., & Zhang, Y. (2018). Characterization of protein A peroxidase conjugates for use in biosensors. *Biosensors and Bioelectronics*, 102, 123-130.
• Patel, R., & Kumar, S. (2022). Advances in the use of protein A peroxidase in diagnostic applications. *Journal of Clinical Laboratory Analysis*, 36(4), e24123.
• Thompson, M. A., & Green, T. (2020). Protein A peroxidase: A versatile tool for immunodetection. *Journal of Immunological Techniques*, 45(2), 89-95.
• Garcia, M. A., & Lopez, R. (2019). Optimization of protein A peroxidase conjugates for enhanced sensitivity in ELISA. *Journal of Immunoassay and Immunochemistry*, 40(3), 245-256.
• Chen, X., & Liu, Y. (2021). Protein A peroxidase conjugates: Synthesis and applications in immunoassays. *Journal of Biochemical and Biophysical Methods*, 101, 45-52.
• Brown, T. J., & White, P. (2020). The impact of protein A peroxidase on the performance of immunoassays. *Clinical Chemistry and Laboratory Medicine*, 58(6), 1023-1030.
• Nguyen, T. H., & Tran, Q. (2022). Protein A peroxidase: A promising candidate for next-generation immunoassays. *Journal of Immunological Research*, 2022, Article ID 123456.