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Rabbit Recombinant Monoclonal CD21 antibody. Suitable for IHC-P, IP, WB, ICC/IF and reacts with Human samples. Cited in 38 publications.


Images

Western blot - Anti-CD21 antibody [EP3093] (AB75985), expandable thumbnail
  • Immunoprecipitation - Anti-CD21 antibody [EP3093] (AB75985), expandable thumbnail
  • Immunocytochemistry/ Immunofluorescence - Anti-CD21 antibody [EP3093] (AB75985), expandable thumbnail
  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [EP3093] (AB75985), expandable thumbnail

Publications

Key facts

Isotype
IgG
Host species
Rabbit
Storage buffer

pH: 7.2 - 7.4
Preservative: 0.05% Sodium azide
Constituents: 50% Tissue culture supernatant, 40% Glycerol (glycerin, glycerine), 9.85% Tris glycine, 0.1% BSA

Form
Liquid
Clonality
Monoclonal

Immunogen

  • The exact immunogen used to generate this antibody is proprietary information.

Reactivity data

Select an application
Product promiseTestedExpectedPredictedNot recommended
IHC-PIPWBICC/IF
Human
Tested
Tested
Tested
Tested

Tested
Tested

Species
Human
Dilution info
1/8000
Notes

For unpurified use at dilution 1/250 to 1/500

Perform heat-mediated antigen retrieval before commencing with IHC staining protocol.

Tested
Tested

Species
Human
Dilution info
1/100
Notes

-

Tested
Tested

Species
Human
Dilution info
1/2000 - 1/5000
Notes

-

Tested
Tested

Species
Human
Dilution info
1/50
Notes

For unpurified use at dilution 1/250 to 1/500

Associated Products

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Target data

Function

Serves as a receptor for various ligands including complement component CD3d, HNRNPU OR IFNA1 (PubMed:1849076, PubMed:21527715, PubMed:7753047). When C3d is bound to antigens, attaches to C3d on B-cell surface and thereby facilitates the recognition and uptake of antigens by B-cells (PubMed:21527715). This interaction enhances B-cell activation and subsequent immune responses. Forms a complex with several partners on the surface of B-cells including CD19, FCRL5 and CD81, to form the B-cell coreceptor complex that plays a crucial role in B-cell activation and signaling (PubMed:1383329, PubMed:30107486). Induces also specific intracellular signaling separately from the BCR and CD19 by activating the tyrosine kinase SRC, which then phosphorylates nucleolin/NCL and triggers AKT and GSK3 kinase activities in a SYK/CD19-independent manner (PubMed:12938232). Acts as a ligand for CD23 (FcepsilonRII), a low-affinity receptor for IgE, which is expressed on B-cells and other immune cells, and thus participates in the regulation of IgE production (PubMed:1386409). (Microbial infection) Acts as a receptor for Epstein-Barr virus.

Alternative names

CD21, C3DR, CR2, Complement receptor type 2, Cr2, Complement C3d receptor, Epstein-Barr virus receptor, EBV receptor

Recommended products

Rabbit Recombinant Monoclonal CD21 antibody. Suitable for IHC-P, IP, WB, ICC/IF and reacts with Human samples. Cited in 38 publications.

Key facts

Isotype
IgG
Form
Liquid
Clonality
Monoclonal
Immunogen
  • The exact immunogen used to generate this antibody is proprietary information.
Clone number
EP3093
Purification technique
Affinity purification Protein A
Concentration
Loading...

Storage

Shipped at conditions
Blue Ice
Appropriate short-term storage duration
1-2 weeks
Appropriate short-term storage conditions
+4°C
Appropriate long-term storage conditions
-20°C
Aliquoting information
Upon delivery aliquot
Storage information
Avoid freeze / thaw cycle

Notes

Our RabMAb® technology is a patented hybridoma-based technology for making rabbit monoclonal antibodies. For details on our patents, please refer to RabMAb® patents.

This product is a recombinant monoclonal antibody, which offers several advantages including:

  • - High batch-to-batch consistency and reproducibility
  • - Improved sensitivity and specificity
  • - Long-term security of supply
  • - Animal-free batch production

For more information, read more on recombinant antibodies.

Rat: We have preliminary internal testing data to indicate this antibody may not react with this species. Please contact us for more information.

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.
Activity summary

CD21 also known as complement receptor type 2 (CR2) or BU32 is a protein primarily expressed on the surface of B cells and some T cells. It functions as a receptor for complement component C3d EBV (Epstein-Barr Virus) and IFN-α. CD21 weighs approximately 145 kDa and belongs to the membrane protein family. Detection of CD21 can be done via immunohistochemistry (IHC) and blood tests. This marker is valuable for identifying cell populations that have roles in immune responses.

Biological function summary

Complement receptor type 2 is key in the immune system by facilitating B cell activation and proliferation. CD21 forms complexes with CD19 and CD81 increasing the sensitivity of B cells to antigens. This interaction enhances signal transduction enabling B lymphocytes to respond effectively to pathogens. The protein also plays a role in regulating immune tolerance and maintaining humoral immunity being important not only in immune defense but also in preventing autoimmunity.

Pathways

CD21 interacts with complement activation and immune response pathways. It connects with CD19 in a pivotal role where it further amplifies signaling in B lymphocytes. This interaction strengthens the downstream signaling of BCR (B cell receptor) important for antibody production. CD21 contributes to bridging the innate and adaptive immunological pathways by engaging components like C3d.

Associated diseases and disorders

CD21 shows significant relevance in systemic lupus erythematosus (SLE) and some B cell lymphomas. Deficiencies or mutations in CD21 can lead to defective immune responses and increased susceptibility to autoimmune conditions such as SLE where CD19 is also implicated. Furthermore in Epstein-Barr Virus infections CD21 serves as an entry receptor facilitating pathogen establishment which can result in chronic conditions or even malignancies.

Product promise

We are dedicated to supporting your work with high quality reagents and we are here for you every step of the way should you need us.

In the unlikely event of one of our products not working as expected, you are covered by our product promise.

Full details and terms and conditions can be found here:
Terms & Conditions.

4 product images

  • Western blot - Anti-CD21 antibody [EP3093] (ab75985), expandable thumbnail

    Western blot - Anti-CD21 antibody [EP3093] (ab75985)

    All lanes: Western blot - Anti-CD21 antibody [EP3093] (ab75985) at 1/20000 dilution

    Lane 1: Daudi (Human Burkitt's lymphoma lymphoblast) whole cell lysate at 20 µg

    Lane 2: Raji (Human Burkitt's lymphoma B lymphocyte) whole cell lysate at 20 µg

    Secondary

    All lanes: Western blot - Goat Anti-Rabbit IgG H&L (HRP) (Goat Anti-Rabbit IgG H&L (HRP) ab97051) at 1/20000 dilution

    Predicted band size: 113 kDa

  • Immunoprecipitation - Anti-CD21 antibody [EP3093] (ab75985), expandable thumbnail

    Immunoprecipitation - Anti-CD21 antibody [EP3093] (ab75985)

    Purified ab75985 at 1/100 dilution (2μg) immunoprecipitating CD21 in Daudi whole cell lysate.
    Lane 1 (input): Daudi (Human Burkitt's lymphoma lymphoblast) whole cell lysate 10μg
    Lane 2 (+): ab75985 + Daudi whole cell lysate.
    Lane 3 (-): Rabbit monoclonal IgG (Rabbit IgG, monoclonal [EPR25A] - Isotype Control ab172730) instead of ab75985 in Daudi whole cell lysate.
    VeriBlot for IP Detection Reagent (HRP) (VeriBlot for IP Detection Reagent (HRP) ab131366) (1/1000 dilution) was used for Western blotting.
    Blocking Buffer and concentration: 5% NFDM/TBST.
    Diluting buffer and concentration: 5% NFDM/TBST.
    Observed band size: 155 kDa
    The band at around 15kDa could be cleavage form. (PMID: 9647256)

    All lanes: Immunoprecipitation - Anti-CD21 antibody [EP3093] (ab75985)

    Predicted band size: 113 kDa

  • Immunocytochemistry/ Immunofluorescence - Anti-CD21 antibody [EP3093] (ab75985), expandable thumbnail

    Immunocytochemistry/ Immunofluorescence - Anti-CD21 antibody [EP3093] (ab75985)

    Immunocytochemistry analysis of Raji (Human Burkitt's lymphoma B lymphocyte) cells labeling CD21 with Purified ab75985 at 1:50 dilution (10 μg/ml). Cells were fixed in 4% Paraformaldehyde and permeabilized with 0.1% tritonX-100. Cells were counterstained with Alexa Fluor® 594 Anti-alpha Tubulin antibody [DM1A] - Microtubule Marker ab195889 Anti-alpha Tubulin antibody [DM1A]+H21:L21 - Microtubule Marker (Alexa Fluor® 594) 1:200 (2.5 μg/ml). Goat anti rabbit IgG (Alexa Fluor® 488, Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) ab150077) was used as the secondary antibody at 1:1000 (2 μg/ml) dilution. DAPI (blue) was used as nuclear counterstain. PBS instead of the primary antibody was used as the secondary antibody only control.

  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [EP3093] (ab75985), expandable thumbnail

    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [EP3093] (ab75985)

    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of human tonsil tissue sections labeling CD21 with Purified ab75985 at 1:8000 dilution (0.066 μg/ml). Heat mediated antigen retrieval was performed using Heat mediated antigen retrieval using Bond™ Epitope Retrieval Solution 1 (pH 6.0) . Tissue was counterstained with Hematoxylin. Rabbit specific IHC polymer detection kit HRP/DAB (Rabbit specific IHC polymer detection kit HRP/DAB ab209101) secondary antibody was used at 1:0 dilution. PBS instead of the primary antibody was used as the negative control.

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Product protocols

For this product, it's our understanding that no specific protocols are required. You can:

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