• Product name
    Anti-CD20 antibody [L26]
    See all CD20 primary antibodies
  • Description
    Mouse monoclonal [L26] to CD20
  • Host species
  • Tested applications
    Suitable for: WB, IP, IHC-P, IHC-Fr, ICC/IF, Flow Cytmore details
  • Species reactivity
    Reacts with: Human
  • Immunogen

    Human tonsil B cells.

  • Positive control
    • Tonsil.



Our Abpromise guarantee covers the use of ab9475 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
WB 1/100 - 1/750. Predicted molecular weight: 33 kDa.
IP 1/100 - 1/750.
IHC-P 1/20 - 1/50.
IHC-Fr 1/20 - 1/50.
ICC/IF Use at an assay dependent dilution. PubMed: 21825174
Flow Cyt Use at an assay dependent dilution.

ab170191 - Mouse monoclonal IgG2a, is suitable for use as an isotype control with this antibody.



  • Function
    This protein may be involved in the regulation of B-cell activation and proliferation.
  • Tissue specificity
    Expressed on B-cells.
  • Involvement in disease
    Defects in MS4A1 are the cause of immunodeficiency common variable type 5 (CVID5) [MIM:613495]; also called antibody deficiency due to CD20 defect. CVID5 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 MS4A family.
  • Post-translational
    Phosphorylated. Might be functionally regulated by protein kinase(s).
  • Cellular localization
  • Information by UniProt
  • Database links
  • Alternative names
    • APY antibody
    • ATOPY antibody
    • B lymphocyte antigen CD20 antibody
    • B Lymphocyte Cell Surface Antigen B1 antibody
    • B-lymphocyte antigen CD20 antibody
    • B-lymphocyte cell-surface antigen B1 antibody
    • B-lymphocyte surface antigen B1 antibody
    • B1 antibody
    • Bp 35 antibody
    • Bp35 antibody
    • CD 20 antibody
    • CD20 antibody
    • CD20 antigen antibody
    • CD20 receptor antibody
    • CD20_HUMAN antibody
    • CVID5 antibody
    • Fc epsilon receptor I beta chain antibody
    • Fc Fragment of IgE high affinity I receptor for beta polypeptide antibody
    • FCER1B antibody
    • High affinity immunoglobulin epsilon receptor subunit beta antibody
    • IgE Fc receptor subunit beta antibody
    • IGEL antibody
    • IGER antibody
    • IGHER antibody
    • LEU 16 antibody
    • LEU16 antibody
    • leukocyte surface antigen Leu 16 antibody
    • Leukocyte surface antigen Leu-16 antibody
    • Ly44 antibody
    • Membrane spanning 4 domains A1 antibody
    • Membrane spanning 4 domains subfamily A member 2 antibody
    • Membrane-spanning 4-domains subfamily A member 1 antibody
    • MGC3969 antibody
    • MS4A1 antibody
    • MS4A2 antibody
    • S7 antibody
    see all


  • Immunohistochemical analysis of paraffin embedded human tonsil tissue with ab9475 at 1 in 50 dilution.

  • Human peripheral blood lymphocytes stained with ab9475 (red line). Human whole blood was processed using a modified protocol based on Chow et al, 2005 (PMID: 16080188). In brief, human whole blood was fixed in 4% formaldehyde (methanol-free) for 10 min at 22°C. Red blood cells were then lyzed by the addition of Triton X-100 (final concentration - 0.1%) for 15 min at 37°C. For experimentation, cells were treated with 50% methanol (-20°C) for 15 min at 4°C. Cells were then incubated with the antibody (ab9475, 0.1μg/1x106 cells) for 30 min at 4°C. The secondary antibody used was Alexa Fluor® 488 goat anti-mouse IgG (H&L) (ab150113) at 1/2000 dilution for 30 min at 4°C. Isotype control antibody (black line) was mouse IgG2a [ICIGG2A] (ab91361, 0.1μg/1x106 cells) used under the same conditions. Unlabelled sample (blue line) was also used as a control. Acquisition of >30,000 total events were collected using a 20mW Argon ion laser (488nm) and 525/30 bandpass filter. Gating strategy - peripheral blood lymphocytes.

  • ab9475 - immunohistochemistry

    Formalin fixed paraffin embedded human tonsil stained with CD20, B cell using ABC and Fast Red chromagen.

  • CD20 associates with phosphorylated proteins after BCR stimulation. Ramos cells were unstimulated or stimulated with F(ab')2 anti-Igµ for the times and temperatures indicated. Cells were lysed in digitonin, and CD20 was Immunoprecipitated from cleared lysates. Immunoprecipitates were probed using anti-phosphotyrosine (ptyr) (n = 4). The membranes were stripped and reprobed for CD20 using ab9475 (lower panel).


This product has been referenced in:
  • Moreno MA  et al. Molecular signature of Epstein-Barr virus infection in MS brain lesions. Neurol Neuroimmunol Neuroinflamm 5:e466 (2018). Read more (PubMed: 29892607) »
  • Gallo A  et al. Targeting the Ca(2+) Sensor STIM1 by Exosomal Transfer of Ebv-miR-BART13-3p is Associated with Sjögren's Syndrome. EBioMedicine 10:216-26 (2016). ICC/IF ; Human . Read more (PubMed: 27381477) »

See all 17 Publications for this product

Customer reviews and Q&As

The localization of the epitope is located in the cytoplasmic domain.

Immunocytochemistry/ Immunofluorescence
Blocking step
BSA as blocking agent for 1 hour(s) and 0 minute(s) · Concentration: 0.5% · Temperature: 22°C
Human Cell (Daudi and Jurkat)
Daudi and Jurkat
Yes - 0.5% Triton X-100

Ms. Natalie Erdmann

Verified customer

Submitted Mar 19 2015

Thank you for your email.

There may be some antibodies where I might have suggested the human tissues or cells. I apologize for this. I have included the positive control information irrespective of species so similar mouse tissues sections ca...

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Thank you for contacting us.

The positive control for ab36392 is IL2 activatedcultured NK cells.

ab9918; human tonsil sections, human cervical squamous cell carcinoma section

ab34674; human artery or colon tissue sections
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Thank you for contacting Abcam.

The antibody ab9475, is supplied as a tissue culture supernatant, not a as a purified antibody. Due to this we are unable to determine the amount of antibody present within the sample, as other non-specific prot...

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Thank you for your inquiry.

When stored at +4C you can use the antibody dilution several times in the same application (about 3-5x). If you encounter any difficulties though, it is recommended to use a fresh aliquot/dilution of the primary a...

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Thank you for your enquiry.

We have a number of monoclonal antibodies to CD20. We do not have a full length CD20 protein but we do have 2 small peptides derived from CD20, these are catalog numbers ab97360 and ab22803.

Feel free to ...

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Abcam guarantees this product to work in the species/application used in this Abreview.
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections)
Human Tissue sections (tonsil)
Antigen retrieval step
Heat mediated - Buffer/Enzyme Used: Citrate pH 6.0
Blocking step
Serum as blocking agent for 10 minute(s) · Concentration: 1.5%

Abcam user community

Verified customer

Submitted Sep 26 2008

Abcam guarantees this product to work in the species/application used in this Abreview.
Western blot
Human Cell lysate - other (SD1 and REH cell plasma membrane prep)
Loading amount
3.5 µg
SD1 and REH cell plasma membrane prep
Blocking step
BSA as blocking agent for 1 hour(s) and 0 minute(s) · Concentration: 5% in PBS-

Dr. Mark Holland

Verified customer

Submitted May 29 2007

Abcam guarantees this product to work in the species/application used in this Abreview.
Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections)
Human Tissue sections (Tonsil)
Antigen retrieval step
Heat mediated
Blocking step
Other as blocking agent for 20 minute(s) · Concentration: 10%

Dr. Jill Henning

Verified customer

Submitted Jul 25 2006


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