Anti-CD81 antibody [1D6] - Low endotoxin, Azide free (ab35026)


  • Product name

    Anti-CD81 antibody [1D6] - Low endotoxin, Azide free
    See all CD81 primary antibodies
  • Description

    Mouse monoclonal [1D6] to CD81 - Low endotoxin, Azide free
  • Host species

  • Specificity

    ab35026 recognises CD81, a 26kD cell surface antigen and a member of the tetraspanin family.
  • Tested applications

    Suitable for: Flow Cyt, IHC-P, IP, Functional Studies, ICC/IFmore details
    Unsuitable for: WB
  • Species reactivity

    Reacts with: Human, Chimpanzee
  • Immunogen

    Tissue, cells or virus corresponding to Human CD81. Aggregated OCI-LY8 cells.

  • Positive control

    • Flow Cyt: HAP1-WT cells.
  • General notes

    Ab35026 is a potent CD81 reagent, induces homotypic adhesion and has powerful anti proliferative effects. Endotoxin Level: <0.01 Eu/ug (low endotoxin grade).


  • Form

  • Storage instructions

    Shipped at 4°C. Upon delivery aliquot and store at -20°C. Avoid freeze / thaw cycles.
  • Storage buffer

    Preservative: None
    Constituents: PBS, pH 7.4
  • Concentration information loading...
  • Purity

    Protein G purified
  • Purification notes

    This antibody was purified from tissue culture supernatant.
  • Primary antibody notes

    Ab35026 is a potent CD81 reagent, induces homotypic adhesion and has powerful anti proliferative effects. Endotoxin Level: <0.01 Eu/ug (low endotoxin grade).
  • Clonality

  • Clone number

  • Myeloma

  • Isotype

  • Research areas


Our Abpromise guarantee covers the use of ab35026 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
Flow Cyt 1/10.

Use 10µl of the suggested working dilution to label 106 cells in 100µl.
ab170190 - Mouse monoclonal IgG1, is suitable for use as an isotype control with this antibody.

IHC-P Use at an assay dependent concentration.
IP Use at an assay dependent concentration.
Functional Studies Use at an assay dependent concentration.
ICC/IF Use at an assay dependent concentration.
  • Application notes
    Is unsuitable for WB.
  • Target

    • Function

      May play an important role in the regulation of lymphoma cell growth. Interacts with a 16-kDa Leu-13 protein to form a complex possibly involved in signal transduction. May acts a the viral receptor for HCV.
    • Tissue specificity

      Hematolymphoid, neuroectodermal and mesenchymal tumor cell lines.
    • Involvement in disease

      Defects in CD81 are the cause of immunodeficiency common variable type 6 (CVID6) [MIM:613496]; also called antibody deficiency due to CD81 defect. CVID6 is a primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen. The defect results from a failure of B-cell differentiation and impaired secretion of immunoglobulins; the numbers of circulating B cells is usually in the normal range, but can be low.
    • Sequence similarities

      Belongs to the tetraspanin (TM4SF) family.
    • Post-translational

      Not glycosylated.
    • Cellular localization

    • Information by UniProt
    • Database links

    • Alternative names

      • 26 kDa cell surface protein TAPA 1 antibody
      • 26 kDa cell surface protein TAPA-1 antibody
      • 26 kDa cell surface protein TAPA1 antibody
      • CD 81 antibody
      • CD81 antibody
      • CD81 antigen (target of antiproliferative antibody 1) antibody
      • CD81 antigen antibody
      • CD81 molecule antibody
      • CD81_HUMAN antibody
      • CVID6 antibody
      • S5.7 antibody
      • TAPA 1 antibody
      • TAPA1 antibody
      • Target of the antiproliferative antibody 1 antibody
      • Tetraspanin 28 antibody
      • Tetraspanin-28 antibody
      • Tetraspanin28 antibody
      • Tspan 28 antibody
      • Tspan-28 antibody
      • Tspan28 antibody
      see all


    • Overlay histogram showing HAP1 wildtype (green line) and HAP1-CD81 knockout cells (red line) stained with ab35026. The cells were fixed with 4% formaldehyde (10 min)  and then permeabilized with 0.1% PBS-Triton X-100 for 15 min. The cells were then incubated in 1x PBS / 10% normal goat serum to block non-specific protein-protein interactions followed by the antibody (ab35026, 0.1µg/ml) for 30 min at 22°C. The secondary antibody used was Alexa Fluor® 488 goat anti-mouse IgG (H&L) presorbed (ab150117) at 1/2000 dilution for 30 min at 22°C.

      A mouse IgG1 isotype control antibody  (ab170190) was used at the same concentration and conditions as the primary antibody (HAP1 wildtype - black line, HAP1-CD81  knockout - grey line). Unlabelled sample was also used as a control (this line is not shown for the purpose of simplicity).

      Acquisition of >5,000 events were collected using a 50 mW Blue laser (488nm) and 530/30 bandpass filter.

      This antibody can also be used in HAP1 cells fixed with 80% methanol (5 min), permeabilized with 0.1% PBS-Triton X-100 for 15 min under the same conditions.

    • ab35026 staining CD81 in SH-SY5Y were transfected with cDNA encoding CD81 by ICC/IF (Immunocytochemistry/immunofluorescence). Cells were fixed with paraformaldehyde, permeabilized with 0.2% Triton X-100 in PBS and blocked with 3% BSA for 2 hours at room temperature. Samples were incubated with primary antibody (1/100 in PBS + 3% BSA) for 2 hours. An Alexa Fluor® 488-conjugated goat anti-mouse IgG polyclonal (1/300) was used as the secondary antibody.

      See Abreview

    • Flow cytometry analysis of Human peripheral blood lymphocytes, staining CD81 with ab35026 at 1/10 dilution.


    This product has been referenced in:

    • Baruah P  et al. TLR9 Mediated Tumor-Stroma Interactions in Human Papilloma Virus (HPV)-Positive Head and Neck Squamous Cell Carcinoma Up-Regulate PD-L1 and PD-L2. Front Immunol 10:1644 (2019). Read more (PubMed: 31379843) »
    • Ngalame NNO  et al. Arsenic Alters Exosome Quantity and Cargo to Mediate Stem Cell Recruitment Into a Cancer Stem Cell-Like Phenotype. Toxicol Sci 165:40-49 (2018). Read more (PubMed: 30169766) »
    See all 3 Publications for this product

    Customer reviews and Q&As

    1-2 of 2 Abreviews or Q&A

    Immunocytochemistry/ Immunofluorescence
    Human Cell (SH-SY5Y were transfected with cDNA encoding CD81)
    Yes - 0,2% Triton PBS
    SH-SY5Y were transfected with cDNA encoding CD81
    Blocking step
    BSA as blocking agent for 2 hour(s) and 0 minute(s) · Concentration: 3% · Temperature: RT°C

    Abcam user community

    Verified customer

    Submitted Jul 29 2015


    Thank you for contacting us today in regards to the Anti-TAPA1 antibody [1D6] - Azide free (ab35026).

    As discussed over the phone, I have checked into whether the antibody has been used in ICC. I can confirm that the antibody has been used in the staining of HUVEC cells and found to work well in this application. Unfortunately I do not have the exact protocol used, or an image of the results but the antibody should be compatible with this application.

    We would be very interested to hear how you get on with your experiments. If you would like some guidelines as to how to set up your experiments we have quite a good protocol guide which can be accessed from the following link:

    I would also like to draw attention to our Abreview system. If you were to submit the results you have observed with the antibody (by filling in an Abreview, should only take 5-10 minutes), you would rewarded with Abpoints which can be exchanged for either Amazon vouchers or money off your next order with Abcam. You would be rewarded separately for the Western blotting and ICC experiments. For more information on this offer, please follow the link below:

    I hope this has been of help. If I can be of any further assistance, please do not hesitate to let me know.

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