For the best experience on the Abcam website please upgrade to a modern browser such as Google Chrome

Hello. We're improving abcam.com and we'd welcome your feedback.

Hello. We're improving abcam.com and we'd welcome your feedback.

Infomation icon

We haven't added this to the BETA yet

New BETA website

New BETA website

Hello. We're improving abcam.com and we'd welcome your feedback.

Take a look at our BETA site and see what we’ve done so far.

Switch on our new BETA site

Now available

Search and browse selected products

  • A selection of primary antibodies

Purchase these through your usual distributor

In the coming months

  • Additional product types
  • Supporting content
  • Sign in to your account
  • Purchase online
United States
Your country/region is currently set to:

If incorrect, please enter your country/region into the box below, to view site information related to your country/region.

Call (888) 77-ABCAM (22226) or contact us
Need help? Contact us

  • My account
  • Sign out
Sign in or Register with us

Welcome

Sign in or

Don't have an account?

Register with us
My basket
Quick order
Abcam homepage

  • Research Products
    By product type
    Primary antibodies
    Secondary antibodies
    ELISA and Matched Antibody Pair Kits
    Cell and tissue imaging tools
    Cellular and biochemical assays
    Proteins and Peptides
    By product type
    Proteomics tools
    Agonists, activators, antagonists and inhibitors
    Cell lines and Lysates
    Multiplex miRNA assays
    Multiplex Assays
    By research area
    Cancer
    Cardiovascular
    Cell Biology
    Epigenetics
    Metabolism
    Developmental Biology
    By research area
    Immunology
    Microbiology
    Neuroscience
    Signal Transduction
    Stem Cells
  • Customized Products & Partnerships
    Customized Products & Partnerships

    Customized products and commercial partnerships to accelerate your diagnostic and therapeutic programs.

    Customized products

    Partner with us

  • Support
    Support hub

    Access advice and support for any research roadblock

    View support hub

    Protocols

    Your experiments laid out step by step

    View protocols

  • Events
    • Conference calendar
    • Cancer
    • Cardiovascular
    • Epigenetics & Nuclear signaling
    • Immunology
    • Neuroscience
    • Stem cells
    • Tradeshows
    • Scientific webinars
    Keep up to date with the latest events

    Full event breakdown with abstracts, speakers, registration and more

    View global event calendar

  • Pathways
    Cell signalling pathways

    View all pathways

    View all interactive pathways

Western blot coomassie blue stain

CD31 target tips

Related

  • Browse by Target

    ​CD31 (cluster of differentiation 31) is a transmembrane protein encoded by the PECAM1 (platelet endothelial cell adhesion molecule) gene. CD31 has essential roles in platelet biology, signal transduction, as well as leukocyte and endothelial cell biology.1 

    Overview​​

    • Protein function, expression, and isoforms 

    • Western Blot tips

    ​Sample preparation

    Electrophoresis

    Transferring

    Recommended controls

    • IHC tips

    ​Sample fixation

    Antibody incubation 

    Recommended controls

    • ICC tips

    ​Sample fixation

    Antibody incubation

    Recommended controls

    • References

    ​

    ​​

    ​​Protein function, expressions, and isoforms

    Protein function

    • CD31 is a cell adhesion molecule that is required for leukocyte transendothelial migration under most inflammatory conditions. 2 3
    • Heterophilic interaction with CD177 plays a role in the transendothelial migration of neutrophils. 3 
    • ​Homophilic ligation of PECAM1 prevents macrophage-mediated phagocytosis of neighboring viable leukocytes by transmitting a detachment signal. 4
    • Promotes macrophage-mediated phagocytosis of apoptotic leukocytes by tethering them to the phagocytic cells; PECAM1-mediated detachment signal appears to be disabled in apoptotic leukocytes. 4
    • Modulates bradykinin receptor BDKRB2 activation. Regulates bradykinin- and hyperosmotic shock-induced ERK1/2 activation in endothelial cells. 5

    ​Expression

    • Expressed on platelets, leukocytes, neutrophils 3, human umbilical vein endothelial cells (HUVECs). 2 3
    • CD31 is primarily concentrated at the borders between endothelial cells. 6 7
    • Isoform long predominates in all tissues examined. 8
    ​​Isoforms
    • Human: Isoform 1-6: 79-83kD (predicted)
    • Mouse: Isoform 1-4: 69.8-81.3kD (predicted)


    ​

    Western blot tips

    CD31 is a transmembrane protein 3, 7 that requires special treatment of samples in western blot. It contains many post-translational modifications, including glycosylations and phosphorylations 2, 7, 9,10,11,12,

    • The actual band size is around 130kD, different from the predicted 79-83kD
    • To confirm the band is indeed CD31, you can treat with phosphatase and PGNase F if necessary. This treatment will break up these post-translational modifications.
    Sample preparation
    • Add protease inhibitors to prevent protein degradation.
    • Keep samples on ice throughout the process.
    • Perform a Bradford assay, a Lowry assay or a bicinchoninic acid (BCA) assay to determine the protein concentration.

    Back to top

    Electrophoresis

    • Run samples in 8% or lower separating gel.
    • Load 20 – 50 μg total protein per lane.

    Back to top

    Transferring 
    • We recommend adding SDS to a final concentration of 0.1% in the transfer buffer.
    • Determine whether the transfer is successful by visualization of proteins in membranes using Ponceau S.

    Back to top

    Recommended controls

    Positive: HUVEC and Jurkat cell lysates (ab7899); Human spleen and kidney tissue lysate.

    Negative: NIH/3T3 whole cell lysate (ab7179)

    Back to top

    ​​


    ​​IHC tips

    Immunostaining CD31 can be used to help identify blood vessels and endothelial cells, where this protein tends to be most concentrated. Pathologists use it to identify vascular origin of tumors, although nodal sinuses may also show a signal 13. CD31 is also used to identify vascular invasion 14, 15 and assess the micro-vessel density of tumors 16​.​

    Sample fixation
    • The ideal fixation time will depend on the size of the tissue block and type of tissue, but  18–24 hours is suitable for most samples.

    ​Back to top

    Antibody incubation
    • It is recommended to optimize antibody dilution in preliminary experiments according to datasheets.

    Back to top

    Recommended controls

    Positive: Human tonsil tissue

    Back to top


    ​

    ICC tips


    CD31 can be used as a biomarker for endothelial cells. It is widely used to confirm the cell type and co-localization of proteins of interest in immunocytochemistry.

    Sample fixation
    • We recommend fixing the cells in 4% PFA for 20 minutes at room temperature.
    • Be sure not to over-fix your samples, as this will reduce the signal.

    Back to top

    Antibody incubation
    • If using fluorescent detection, add 0.3M glycine to the sample. This will quench autofluorescence caused by aldehydes.

    Back to top

    Recommended controls

    Positive: HUVEC cells

    Back to top 

    ​​

    References

    1. Lertkiatmongkol, P., Liao, D., Mei, H., Hu, Y., Newman, P.J. Endothelial functions of platelet/endothelial cell adhesion molecule-1 (CD31). Curr Opin Hematol. 23, 253-259 (2016).  
    2. Dasgupta, B., Dufour, E., Mamdouh, Z., Muller, W.A. A novel and critical role for tyrosine 663 in platelet endothelial cell adhesion molecule-1 trafficking and transendothelial migration. J Immunol. 182, 5041-51 (2009)
    3. Sachs, U.J., Andrei-Selmer, C.L., Maniar, A. et al. The neutrophil-specific antigen CD177 is a counter-receptor for platelet endothelial cell adhesion molecule-1 (CD31). J Biol Chem. 282, 23603-12 (2007). 
    4. Brown, S., Heinisch, I., Ross, E., Shaw, K., Buckley, C.D., Savill, J. Apoptosis disables CD31-mediated cell detachment from phagocytes promoting binding and engulfment. Nature. 418, 200-3 (2002) 
    5. Yeh, J.C., Otte, L.A., Frangos, J.A. Regulation of G protein-coupled receptor activities by the platelet-endothelial cell adhesion molecule, PECAM-1. Biochemistry. 26, 9029-39 (2008)
    6. Bergom, C., Paddock, C., Gao, C., Holyst, T., Newman, D.K., Newman P.J. An alternatively spliced isoform of PECAM-1 is expressed at high levels in human and murine tissues, and suggests a novel role for the C-terminus of PECAM-1 in cytoprotective signaling. J Cell Sci. 121, 1235-42 (2008)
    7. Paddock, C., Lytle, B.L., Peterson, F.C., Holyst, T., Newman, P.J., Volkman, B.F., Newman, D.K. Residues within a lipid-associated segment of the PECAM-1 cytoplasmic domain are susceptible to inducible, sequential phosphorylation. Blood. 117, 6012-23 (2011)
    8. Wang, Y., Su, X., Sorenson, C.M., SheibaniN. Tissue-specific distributions of alternatively spliced human PECAM-1 isoforms. Am J Physiol Heart Circ Physiol. 284, H1008-17 (2003) 
    9. Paddock, C., Zhou, D., Lertkiatmongkol, P., Newman, P.J., Zhu, J. Structural basis for PECAM-1 homophilic binding. Blood. 127, 1052-61 (2016)
    10. Wollscheid, B., Bausch-Fluck, D., Henderson, C., O'Brien, R., Bibel, M., Schiess, R., Aebersold, R., Watts, J.D. Mass-spectrometric identification and relative quantification of N-linked cell surface glycoproteins. Nat Biotechnol. 27, 378-86 (2009)
    11. Chen, R., Jiang, X., Sun, D., Han, G., Wang, F., Ye, M., Wang, L., Zou, H. Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry. J Proteome Res. 8, 651-61 (2009) 
    12. Famiglietti, J., Sun, J., DeLisser, H.M., Albelda, S.M. Tyrosine residue in exon 14 of the cytoplasmic domain of platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) regulates ligand binding specificity. J Cell Biol. 138, 1425-35 (1997)
    13. Hattori, H. Caution should be taken in using CD31 for distinguishing the vasculature of lymph nodes. J Clin Pathol. 56, 638-9 (2003)
    14. Alexander-Sefre, F., Singh, N., Ayhan, A., Salveson, H.B., Wilbanks, G., Jacobs, I.J. Detection of tumour lymphovascular space invasion using dual cytokeratin and CD31 immunohistochemistry. J Clin Pathol. 56, 786-8 (2003) 
    15. Kurtz, K.A., Hoffman, H.T., Zimmerman, M.B., Robinson, R.A. Perineural and vascular invasion in oral cavity squamous carcinoma: increased incidence on re-review of slides and by using immunohistochemical enhancement. Arch Pathol Lab Med. 129, 354-9. (2005)
    16. El-Gohary, Y.M., Metwally, G., Saad, R.S., Robinson, M.J., Mesko, T., Poppiti, R.J. Prognostic significance of intratumoral and peritumoral lymphatic density and blood vessel density in invasive breast carcinomas. Am J Clin Pathol. 129, 578-86. (2008)

    ​

    Download these tips as a PDF

    • In English
    • In Mandarin
    Find full information on working with CD-31:
    In English (link to pdf)
    In Mandarin (Link to pdf)

    ​


    Get resources and offers direct to your inbox Sign up
    A-Z by research area
    • Cancer
    • Cardiovascular
    • Cell biology
    • Developmental biology
    • Epigenetics & Nuclear signaling
    • Immunology
    • Metabolism
    • Microbiology
    • Neuroscience
    • Signal transduction
    • Stem cells
    A-Z by product type
    • Primary antibodies
    • Secondary antibodies
    • Biochemicals
    • Isotype controls
    • Flow cytometry multi-color selector
    • Kits
    • Loading controls
    • Lysates
    • Peptides
    • Proteins
    • Slides
    • Tags and cell markers
    • Tools & Reagents
    Help & support
    • Support
    • Make an Inquiry
    • Protocols & troubleshooting
    • Placing an order
    • RabMAb products
    • Biochemical product FAQs
    • Training
    • Browse by Target
    Company
    • Corporate site
    • Investor relations
    • Company news
    • Careers
    • About us
    • Blog
    Events
    • Tradeshows
    • Conferences
    International websites
    • abcam.cn
    • abcam.co.jp

    Join with us

    • LinkedIn
    • facebook
    • Twitter
    • YouTube
    • Terms of sale
    • Website terms of use
    • Cookie policy
    • Privacy policy
    • Legal
    • Modern slavery statement
    © 1998-2023 Abcam plc. All rights reserved.