• Product name
    PE / R-Phycoerythrin Conjugation Kit
  • Product overview

    Abcam's PE / R-Phycoerythrin Conjugation Kit provides a simple and quick process to conjugate your primary antibodies with R-PE. R-PE is an orange fluorescent protein which has excitation wavelengths of 496 nm, 535 nm and 566 nm and an emission wavelength of 575 nm.

    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

    Pre-conjugation considerations

    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.


    Amount and volume of antibody

    In view of the large size of PE (240kDa), the amount of antibody used in a labeling reaction must always be less than the amount of PE, in order that the PE is in a slight molar excess. The best ratio for any new antibody reagent must be determined by experimentation but 50-60µg of IgG antibody for every 100µg of PE usually gives optimal results. 60µg of antibody corresponds to an Antibody:PE molar ratio of 1:1.
    The volume in which the antibody is added ideally should be around 40µl. Where the concentration of antibody is relatively low, and where it is impractical to concentrate the antibody, up to twice the volume stated above may be added without any significant loss in conjugation efficiency.



    • Before you add antibody to the R-PE mix, add 1µl of Modifier reagent for each 10µl of antibody to be labeled. Mix gently. 
    • Remove the screw cap from the vial of R-PE 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

    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 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).



  • Flow cytometry histogram showing integrin beta-3 positive population of platelets from wildtype and knockout mice. Integrin beta-3 antibody was conjugated using EasyLink R-Phycoerythrin conjugation kit (ab102918). Flow cytometry was performed using platelets from wild type and integrin beta-3 knockout mice. Mice that expressed beta-3 (shown in red) had a clear shift in FL-2 fluorescence over beta-3 knockout mice (shown in black).



This product has been referenced in:
  • Boopathy GTK  et al. Cavin-2 regulates the activity and stability of endothelial nitric-oxide synthase (eNOS) in angiogenesis. J Biol Chem 292:17760-17776 (2017). Read more (PubMed: 28912276) »
  • McGinn OJ  et al. Targeting the 5T4 oncofetal glycoprotein with an antibody drug conjugate (A1mcMMAF) improves survival in patient-derived xenograft models of acute lymphoblastic leukemia. Haematologica 102:1075-1084 (2017). Read more (PubMed: 28341731) »

See all 5 Publications for this product

Customer reviews and Q&As

Compounds containing amines (such as Tris) compete with the antibody or other protein for the R-Phycoerythrin. Unusually for an amine, Tris has little effect on conjugation efficiency as long as the concentration is 20mM or less. So, if 100 mM (0.1 M)...

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We have the same integrin beta 1 antibody [12G10] that is FITC conjugated as ab150002, just so you know, but we do not have an R-PE conjugated version.

But if you would like to conjugate the ab30394 to ...

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I can confirm that the R-Phycoerythrin (RPE) conjugation kit is indeed free of animal components.

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

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Thank you for contacting us. We have not tested ab75803 in Flow Cytometry and do not have any data regarding suitability in this application. You would have to purify the antibody before conjugating it to remove the BSA or the BSA may be conjugated. Read More

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The EasyLink conjugations require antibody concentrations of at least 1mg/ml. Below that, the conjugation becomes inefficient and you risk wasting the conjugate, not to mention the antibody. For antibodies of low...

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Thank you for contacting us with your question.

Ab102918 has been developed to conjugate antibodies, however it targets available amine groups, so it can conjugate proteins and peptides provided there is at least one aminegroup (lysine) avail...

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We have a PE- conjugated antibody against cytokeratin, catalogue item ab52460:

Click here (or use the following: https://www.abcam.com/index.html?datasheet=52460).

For collagen I, we have on...

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