• Nature
  • Source
  • Conjugation

Associated products


Our Abpromise guarantee covers the use of ab7403 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

  • Applications

    Dot blot


    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections)

    Immunohistochemistry (Frozen sections)



    Western blot

  • Form
  • Additional notes

    Horseradish peroxidase is conjugated to the streptavidin tetramer at ~1:1 molar ratio.

    ab7403 is stable for several weeks at 4°C as an undiluted liquid. Dilute only prior to immediate use.

    This product has been assayed against 1.0 µg of Biotinylated IgG in a standard capture ELISA using a peroxidase substrate as ABTS ab142041 as a substrate for 30 minutes at room temperature. A working dilution of 1:15,000 to 1:60,000 of the reconstitution concentration is suggested for this product. Optimal titers for other applications should be determined by the researcher.


  • Concentration information loading...

Preparation and Storage

  • Stability and Storage

    Shipped at 4°C. Upon delivery aliquot. Store at -20°C long term. Avoid freeze / thaw cycle.

    pH: 7.20
    Preservative: 0.01% Gentamicin sulphate
    Constituents: 0.424% Potassium phosphate, 0.87% Sodium chloride, BSA

General Info

  • Alternative names
    • SA V1
    • SA V2
    • strepavidin
    • Streptavidin V1
    • Streptavidin V2
    see all
  • Relevance
    Streptavidin is a tetrameric protein purified from Streptomyces sp. that binds very tightly to the vitamin biotin with a Kd of ~ 10-14 mol/l. The high affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits.
  • Cellular localization


  • IHC image of Histone H1 staining in a section of formalin-fixed paraffin-embedded [human normal colon]*. The section was pre-treated using pressure cooker heat mediated antigen retrieval with sodium citrate buffer (pH6) for 30mins. The section was then incubated with ab11080, 1/1000 dilution, for 15 mins at room temperature. A goat anti-mouse biotinylated secondary antibody (ab6788, 1/1000 dilution), was used to detect the primary, and visualized using an HRP conjugated ABC system. Streptavidin HRP was used, ab7403 at a 1/10000 dilution. DAB was used as the chromogen (ab103723), diluted 1/100 and incubated for 10min at room temperature. The section was then counterstained with haematoxylin and mounted with DPX. The inset negative control image is taken from an identical assay without primary antibody.

    For other IHC staining systems (automated and non-automated) customers should optimize variable parameters such as antigen retrieval conditions, primary antibody concentration and antibody incubation times.

    *Tissue obtained from the Human Research Tissue Bank, supported by the NIHR Cambridge Biomedical Research Centre

  • The wells were coated with ab200699 at 1µg/ml at 50µl/well overnight at 4°C, followed by a 5% BSA blocking step for 2h RT. Human IgG3 (ab138703) was then added starting at 20 µg/ml and plasma/serum at 1:500 and gradually diluted 1:4, 50µl/well for 2h. Ab201248 was then added at 1:10,000 dilution, 50µl/well for 2h. A HRP-streptavidin (ab7403) was used at 1:10,000 dilution for 1h.


This product has been referenced in:
  • Guo J  et al. Detection and identification of O-GlcNAc-modified proteins using 6-azido-6-deoxy-N-acetyl-galactosamine. Org Biomol Chem 17:4326-4334 (2019). Read more (PubMed: 30976765) »
  • Mitchell LA  et al. PD-L1 checkpoint blockade delivered by retroviral replicating vector confers anti-tumor efficacy in murine tumor models. Oncotarget 10:2252-2269 (2019). Read more (PubMed: 31040917) »
See all 24 Publications for this product

Customer reviews and Q&As

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Western blot
We performed modified biotin switch assay where the biotinylated sulfhydrated proteins were incubated with ab7403 - Streptavidin (HRP) for 1h at room temperature (1:100) and then immunoblotted for detection of sulfhydrated protein status.

Abcam user community

Verified customer

Submitted May 14 2018

A standard sandwich ELISA experiment worked very well by use of ab7403 with 1/30,000 dilution.

Detailed protocol was described below.

*5 uL of human serum was separated with size exclusion chromatography into 10 fractions.
*1st antibody : anti-CD9 (Ancell Corporation)
*Blocking : 5% BSA in PBS
*2nd antibody : Biotinylated anti-CD9 (Ancell Corporation)

*HRP label : ab7403 - Streptavidin HRP, 1/30,000 dilution in 1% BSA/PBS, 30 min, RT

*1-Step Ultra TMB-ELISA Substrate Solution - Pierce
*Measure OD 450 nm

Abcam user community

Verified customer

Submitted Aug 20 2014

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