• 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) »
  • Syed S  et al. Environmental Enteropathy in Undernourished Pakistani Children: Clinical and Histomorphometric Analyses. Am J Trop Med Hyg 98:1577-1584 (2018). Read more (PubMed: 29611507) »
See all 20 Publications for this product

Customer reviews and Q&As

1-10 of 11 Abreviews or Q&A

Western blot
Human Cell lysate - whole cell (Lymphocytes)
Gel Running Conditions
Reduced Denaturing (4-12% Bis-Tris)
Loading amount
20 µg
Blocking step
Milk as blocking agent for 1 hour(s) and 0 minute(s) · Concentration: 5% · Temperature: 25°C

Abcam user community

Verified customer

Submitted Sep 15 2018

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 can used as positive control.

Actually the positive control information for each antibody is present on the datasheet; please check the datasheet. Alternatively, we always follow human protein Atlas database (http://www.proteinatlas.org/index.php). The second option is, searching positive control for other antibodies in catalogue against same target; the cell line or tissue sections tested with those antibodies could also be used as positive control. The third place to search for is literature.

I hope this information will be helpful. Should you have any question please do not hesitate to contact me.

Read More


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

ab15537; HepG2 cells. mouse brain sections, human placenta sections; Human hepatocellular liver carcinoma cell line; Human hepatocarcinoma tissue sections

ab2557; mouse spleen tissue sections

ab9475; human tonsil tissue sections

ab22378; mouse spleen tissue sections

ab51312; Thymus tissue sections, human pancreas tissue sections.

The best database to search for positive control is Human Protein Atlas. Please click the link http://www.proteinatlas.org/index.php

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

Use our products? Submit an Abreview. Earn rewards!

Read More


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 proteins will also be present.

If there is anything else I can help you with, please let me know

Read More


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 antibody.

I hope this information is helpful to you and wish you the best of luck with your research. Please do not hesitate to contact us if you have any questions.

Read More


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 call us at 888-77-ABCAM(22226). My name is Jeremy so feel free to ask for me when you call.

Read More
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

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

1-10 of 11 Abreviews or Q&A

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