PtX™ Protein A (HRP)

Protein A fused to horseradish peroxidase is produced in Nicotiana benthamiana plants and provides a versatile and economical means for detecting antibodies in WB and ELISA applications.

100 µg Sample Size     |     Catalogue Number: CBT_P0002

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Protein A is a highly stable 42 kDa surface protein found in the cell walls of several strains of Staphylococcus aureus. It consists of a single polypeptide chain, composed of five homologous IgG-binding domains that strongly bind Fc regions of IgG from several mammalian species. Due to its high IgG binding affinity, Protein A is commonly used as a reliable method for purifying total IgG from crude protein mixtures or conjugated to reporter enzymes for antibody detection. Our Protein A comes conveniently fused to HRP, allowing for multi-species antibody detection in Western blot, ELISA, and other immunoassay protocols.

Table showing affinity of Protein A to several species’ immunoglobulins. Verified affinity *.


Species Immunoglobulin Protein A binding affinity
Human IgG1 * ++++
IgG2 ++++
IgG3 -
IgG4 ++++
IgM -
IgE * -
Rabbit IgG * +++
Mouse IgG1 * +
IgG2a * ++++
IgG2b +++
IgG3 ++
Rat IgG1 * -
IgG2c +
Alpaca IgG2b * ++++
Chicken IgY * -

Additional information

Available Unit Size

0.1mg, 1mg, 10mg, 100mg, 200mg

Key Benefits

This product is a plant-made, recombinant protein, which offers several advantages including:

  • Binding and detection of several species’ immunoglobulins.
  • Protein is genetically fused for increased reproducibility of results.
  • No animals or animal products are used in the development of this protein.
  • Azide and BSA free.

For more information on plant-made, recombinant monoclonal proteins click here.


Figure 1. ELISA Dose Response curve showing increasing absorbance at 370 nm with increasing amounts of TX™ Recombinant Protein A (HRP) used to detect Human IgG antigen.

Figure 2. Western blot of decreasing amounts of GST antigen (28 kDa) detected with PtX Rabbit Anti-GST Recombinant Antibody at 1: 5 000 and PtX™ Recombinant Protein A (HRP) at 1: 1 000 as secondary detection probe.


Product Name PtX™ Recombinant Protein A (HRP)
Catalogue Number CBT_P0002
Expression Host Nicotiana benthamiana plants
Clonality N/A
Species Staphylococcus aureus
Tag 6xhis tag (C-terminal)
Reporter Protein Horseradish peroxidase (HRP) (N-terminal)
Description This product is recombinantly produced in Nicotiana benthamiana plants via
Agrobacterium tumefaciens mediated infiltration.
Verified Applications Western blot (1: 1 000-1: 2 000)
ELISA (1: 1 000-1: 5 000)
Verified Species Immunoglobulin Affinity   Human IgG1 (++++)
Rabbit IgG (+++)
Mouse IgG1 (+)
Mouse IgG2a (++++)
Alpaca IgG2b (++++)
Concentration 1.0  mg/ml
Form Liquid
Colour Light reddish
Preparation Ready to use
Storage Short term (up to one week): 2 – 8 °C
Long term: Aliquot and store at – 20 °C
Store immediately. Aliquot and avoid multiple freeze thaw cycles.
Storage buffer 0.1  M Phosphate Buffered Saline, pH 7.4. Preservative: None
Purification notes This product was purified using Immobilised metal affinity chromatography (IMAC).
Purity ≥ 85 % as determined by SDS-PAGE
97.06% as determined by Mass Spectrometry
General notes If for any reason the product does not perform as specified, please contact our scientific support team for assistance by emailing

PtX™ | Plant-Based Expression

The biotechnology behind the development and manufacture of this product, transient plant-based expression, effectively turns Nicotiana benthamiana plants into single-use, biodegradable bioreactors. Infiltrating this plant species with Agrobacterium tumefaciens cells, transformed with our proprietary plant expression vectors, allows rapid production of a wide variety of recombinant proteins. Plants are harvested and proteins are extracted by various stages of filtration, clarification, purification, and polishing – resulting in a highly functional final product.

Visit our Technology page to learn more.


  • For Research Use Only.
  • Not for diagnostic or therapeutic use.
  • Not for resale without express authorization.
  • Trademark.

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