• Product name
    Endogenous Avidin/Biotin Blocking Kit
    See all Endogenous Avidin+Biotin Blocking System kits
  • Product overview

    Avidin Biotin Blocking Kit ab64212 blocks signal from endogenous avidin, biotin and biotin-binding proteins in tissues when used with biotin-based IHC detection (eg. with ABC IHC detection kits).

    Find more kits and reagents for antigen retrieval, blocking, signal amplification, visualization, counterstaining, and mounting in the IHC kits and reagents guide.


  • Tested applications
    Suitable for: IHC-P, ICC/IF, IHC-Frmore details


  • Storage instructions
    Store at +4°C. Please refer to protocols.
  • Storage buffer
    Preservative: 0.08% Sodium azide
    Constituent: Avidin
  • Components 15 ml
    Avidin Block 1 x 15ml
    Biotin Block 1 x 15ml
  • Research areas
  • Relevance
    Some cells, and tissues such as kidney, liver and spleen, contain endogenous biotin. Using an avidin-biotin staining method may result in high, non-specific background staining. A significant reduction of this non-specific background can be obtained by pre-treatment of cells/tissues with avidin/biotin blocking reagents prior to the incubation of biotinylated antibody.


Our Abpromise guarantee covers the use of ab64212 in the following tested applications.

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

Application Abreviews Notes
IHC-P Use at an assay dependent concentration.
ICC/IF Use at an assay dependent concentration.
IHC-Fr Use at an assay dependent concentration.


  • Immunohistochemical analysis staining HTRA1 in mouse bone tissue sections. Tissue sections were dewaxed, rehydrated and treated with Endogenous Avidin/Biotin Blocking Kit (ab64212), 3% H2Oand normal swine serum. Tissue sections were then incubated with a polyclonal anti-HTRA1 antibody for 1 hour at 37°C. After PBS wash, tissue sections are incubated with biotinylated swine anti-rabbit IgG for 45 minutes at 37°C and further incubated for 30 minutes after washing. With Vectastatin. Sections were developed using DAB and counterstained using Harris modified hematoxylin. 


This product has been referenced in:
  • Peng C  et al. Synchronous primary sigmoid colon cancer and primary thyroid cancer followed by a malignant tumor of the kidney: Case report of multiple primary cancer and review of the literature. Oncol Lett 17:2479-2484 (2019). Read more (PubMed: 30719116) »
  • Hammad S  et al. Confounding influence of tamoxifen in mouse models of Cre recombinase-induced gene activity or modulation. Arch Toxicol 92:2549-2561 (2018). Read more (PubMed: 29974145) »
See all 4 Publications for this product

Customer reviews and Q&As

1-4 of 4 Abreviews or Q&A

helpful kit

Excellent Excellent 5/5 (Ease of Use)
We used this kit to block the non-specific binding of avidin or biotinylated reagents with the endogenous biotin, also their receptors and the avidin binding sites in the tissue.
Its works good and is easy to use.
We used the kit as a ready to use-kit and incubated the samples first with the avidin block for 10minutes and after a washing step with the bioin block for 10minutes.

Abcam user community

Verified customer

Submitted Mar 12 2018


I can confirm that the Avidin Block and Biotin block provided with this kit come ready to use. They should not be diluted.

Once the sections are cut into sections and placed on a slide, the avidin and biotin blocking is done as part of the antibody staining procedure. You will need to pipette enough solution on to cover the tissue section and ensure it does not dry out during incubation. Typically this is usually 50 - 200 ul depending on the size of the section.

There is a protocol provided on the datasheet, see the link in the protocols tab.

Incubate tissue sections with Avidin Block for 10-15 minutes.
Wash 2 times with buffer.
Incubate tissue sections with Biotin Block for 10-15 minutes.
Wash 2 times with buffer
Apply Primary antibody to the tissue sections

I hope this will be helpful. If you have any further questions, please do not hesitate to contact me.

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Thank you for contacting us.

I would not recommend using the normal serum after biotin blocking for fear of introducing biotin to the samples. However if you would like, you may block with normal serum (5-10%) prior to biotin/avidin blocking. As you are not using a secondary you can use any normal serum at hand, donkey, goat, etc.

I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.

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Thank you for your reply.

In this case I would recommend that you quench endogenous biotin/avidin in your tissue prior to staining. We recommend use of our Endogenous Avidin/Biotin Blocking Kit (ab64212).

After blocking with this system, you may incubate your primary antibodies diluted in PSB or TBS.

Use of a mild detergent in your wash solution may also help to reduce background but isn't always neccessary.

More information about our Endogenous Avidin/Biotin Blocking Kit (ab64212) may be found at the location below:


I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.

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