• Product nameBiotin (type A) Conjugation Kit
    See all Biotin (type A) kits
  • Product overview

    Abcam's Biotin (type A) Conjugation Kit provides a simple and quick process to conjugate your primary antibodies with Biotin. It is optimized for assays in which a biotinylated antibody binds to a plate and the bound antibody is then detected using a streptavidin labelled molecule such as Streptavidin-HRP. Free biotin is not a problem in this assay as it will be washed away before the Streptavidin-HRRP is added.

    The conjugated antibody can be used straight away in WB, ELISA, IHC etc.

    Learn more about buffer compatibility, protein/secondary antibody conjugation and labelling chemistry in our FAQs.


  • Notes

    Amount and volume of antibody

    The volume of the antibody sample should ideally be in the range 5-10µl. Antibody concentrations of 1-4mg/ml generally give optimal results, but concentrations and volumes outside the suggested ranges have also yielded excellent conjugates.


    1. Before you add antibody to the Biotin (type A) mix, add 1µl of Modifier reagent for each 10µl of antibody to be labeled. Mix gently.
    • Remove the screw cap from the vial of Biotin (type A) mix and pipette the antibody sample (with added Modifier) directly onto the lyophilised material. Resuspend gently by withdrawing and re-dispensing the liquid once or twice using a pipette.
    • Place the cap back on the vial and leave the vial standing for 3 hours in the dark at room temperature (20-25°C). Alternatively, and sometimes more conveniently, conjugations can be set up and left overnight, as the longer incubation time has no negative effect on the conjugate.
    • After incubating for 3 hours (or more), add 1µl of Quencher reagent for every 10µl of antibody used. The conjugate can be used after 30 minutes.

    Storage of conjugates

    Shipped at 4°C. For any new conjugate, initial storage at 4°C is recommended. A preservative may be desirable for long-term storage. Other storage conditions (e.g. frozen at -70°C or stored at -20°C with 50% glycerol) may also be satisfactory. The best conditions for any particular conjugate must be determined by experimentation.

    Sample Buffer

    Ideally, the antibody to be labeled should be in 10-50mM amine-free buffer pH range 6.5 to 8.5. However, many buffers outside these limits of concentration and pH can be accommodated. Modest concentrations of Tris buffer are also tolerated.

    Amine-free buffers, including MES, MOPS, HEPES and phosphate are compatible if they are in the concentration range 10-50mM and have pH values in the range 6.5-8.5, as the addition of EL-Modifier provides the conditions necessary for efficient conjugation. Common non-buffering salts (e.g. sodium chloride), chelating agents (e.g. EDTA), and sugars may be present, as they have no effect on conjugation efficiency. Azide (0.02-0.1%) has little or no effect. If the amine-free buffer is relatively concentrated and outside the pH range 6.6-8.5 you may need to add more Modifier for each 10µl of antibody. Excess Modifier is provided so that you can check the pH of the buffer after the addition of the modifier. Ideally the pH should be around 7.3-7.6, though efficient conjugation occurs anywhere between pH 6.8 and 7.8. Avoid buffer components that are nucleophilic, as these may react with the kit chemicals. If your buffer contains primary amines (e.g. amino acids, ethanolamine) and/or thiols (e.g. mercaptoethanol, DTT), you should consider using our Concentration and Purification Kits (ab102778 or ab102784). (Note: Unusually, for an amine, Tris has little effect on conjugation efficiency as long as the concentration is 20mM or less).


    Labeling of the antibody will not work if the conjugation blocks the active paratope. This situation is rare.


    The antibody to be labelled should be purified, in an appropriate buffer for conjugation and at a suitable concentration, as described in the protocol booklet. If not, consider using our antibody purification and concentration kits.

  • Tested applicationsSuitable for: Conjugationmore details



    Our Abpromise guarantee covers the use of ab102865 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
    Conjugation Use at an assay dependent dilution.

    Biotin (type A) Conjugation Kit images

    • This illustration demonstrates a general procedure and will slightly vary dependent on the conjugate used.


    References for Biotin (type A) Conjugation Kit (ab102865)

    This product has been referenced in:
    • Sano M  et al. The luteotrophic function of galectin-1 by binding to the glycans on vascular endothelial growth factor receptor-2 in bovine luteal cells. J Reprod Dev 61:439-48 (2015). Conjugation . Read more (PubMed: 26155753) »
    • Hashiba K  et al. Galectin-3 contributes to luteolysis by binding to Beta 1 integrin in the bovine corpus luteum. Biol Reprod 91:2 (2014). Conjugation . Read more (PubMed: 24855102) »

    See all 3 Publications for this product

    Product Wall

    Both kits are NH2-reactive but the chemistry is proprietary. There is no need to change the pH to get an efficient reaction; the buffers in the various components of the kit will ensure that the reaction pH is correct.

    The N-terminus (if acces...

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    labeling made very easy

    Excellent Excellent 5/5 (Ease of Use)
    Using the EasyLink Biotin Conjugation Kit was very easy and quick.
    We achieved excelent results in an antibody labeling reaction.
    The epitope-recognition of this antibody is not affected and detection via streptavidin-HRP is very sensitive.

    Dr. Thomas Timm

    Verified customer

    Submitted May 02 2014

    With regard to the labeling efficiency of the biotin kit, each antibody will be conjugated with multiple biotins. Getting up to 6 or 8 biotins per antibody is feasible. It is important to remember that you only need one biotin attached to enable the bi...

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    Thank you very much for contacting us.

    The contents of the antibody buffers of both antibodies as they are currently would most likely cause the conjugation reaction to fail or create poor-quality conjugates. My recommendation would be that th...

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    Thank you for contacting us.

    Unfortunately, we only have the non-conjugated antibody or with a FITC conjugate.

    However, you could conjugate the antibody yourself with one of our biotin conjugation kits. Please see the following dat...

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    Vielen Dank Ihr Interesse an unseren Produkten.

    Unseres Wissens nach wurde ab76447 Anti-PXDN antibody bisher noch nicht in der Flow cytometrie getestet. Falls Sie dies selbst testen möchten, kann ich Ihnen zur Zeit ein spezielles Angebo...

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    Thank you for contacting us.

    There could be a variety of reasons why no signal was observed on the ELISA plate. In order to determine what might be the cause of the issue, it would help if you could please answer some questions about the conj...

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    Merci de nous avoir contactés.

    Le laboratoire vient de me confirmer que l'utilisation des kits EasyLink est déconseillée pour le marquage d'acides aminés.
    Ces kitsciblentles groupes aminés primaires et en...

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    Thank you for contacting us.

    We currently do not offer ab8580 in a buffer which is free of BSA. When using our EasyLink Conjugation Kits concentrations of up to 0.5% BSA and 0.1% gelatin have little effect on the conjugation chemistry. As su...

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    The biggest biotinylation kit we have is ab102863, which will biotinylate up to 1 mg of antibody. This will label just one antibody, not multiple antibodies, as there is only one vial of lyophilized biotin.

    Click here (or use the following: ...

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