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Rabbit Recombinant Monoclonal CD21 antibody. Suitable for Flow Cyt (Intra), WB, IHC-P and reacts with Human samples.

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Images

Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP199] (AB227668), expandable thumbnail
  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (AB227668), expandable thumbnail
  • Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP199] (AB227668), expandable thumbnail
  • Western blot - Anti-CD21 antibody [SP199] (AB227668), expandable thumbnail
  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (AB227668), expandable thumbnail

Key facts

Isotype
IgG
Host species
Rabbit
Storage buffer

pH: 7.6
Preservative: 0.1% Sodium azide
Constituents: 98.9% PBS, 1% BSA

Form
Liquid
Clonality
Monoclonal

Immunogen

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

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Reactivity data

Select an application
Product promiseTestedExpectedPredictedNot recommended
Flow Cyt (Intra)WBIHC-P
Human
Tested
Tested
Tested
Mouse
Predicted
Not recommended
Predicted

Tested
Tested

Species
Human
Dilution info
1/20 - 1/100
Notes

-

Predicted
Predicted

Species
Mouse
Dilution info
-
Notes

-

Tested
Tested

Species
Human
Dilution info
1/150
Notes

-

Not recommended
Not recommended

Species
Mouse
Dilution info
-
Notes

-

Tested
Tested

Species
Human
Dilution info
1/100
Notes

Antigen retrieval: Boil tissue section in 10mM citrate buffer, pH 6.0 for 10 minutes followed by cooling at room temperature for 20 minutes.

Predicted
Predicted

Species
Mouse
Dilution info
-
Notes

-

Associated Products

Select an associated product type

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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 Flow Cyt (Intra), WB, IHC-P and reacts with Human samples.

Key facts

Isotype
IgG
Form
Liquid
Clonality
Monoclonal
Immunogen
  • The exact immunogen used to generate this antibody is proprietary information.
Clone number
SP199
Purification technique
Affinity purification Protein A/G
Concentration
Loading...
Purification notes

Purified from TCS by protein A/G.

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

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

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

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6 product images

  • Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP199] (ab227668), expandable thumbnail

    Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP199] (ab227668)

    Flow cytometry analysis of Raji (Human Burkitt's lymphoma B lymphocyte）labeling CD21 with purified ab227668 at 1/20 dilution (5.1 μg/ml) (red). Cells were fixed with 4% paraformaldehyde and permeabilised with 90% methanol. Goat anti rabbit IgG (Alexa Fluor® 488, Goat Anti-Rabbit IgG H&L (Alexa Fluor® 488) ab150077) at 1/2000 dilution was used as a secondary antibody. Isotype control - Rabbit monoclonal IgG (Rabbit IgG, monoclonal [EPR25A] - Isotype Control ab172730) (black). Unlableled control - Unlabelled cells (blue).

  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (ab227668), expandable thumbnail

    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (ab227668)

    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) analysis of Human tonsil tissue sections labeling CD21 with ab227668 at 1/100 dilution (1.02 μg/ml). Heat mediated antigen retrieval with Citrate buffer (pH 6.0, epitope retrieval solution 1) for 10mins. Goat Anti-Rabbit & Mouse IgG (HRP) was used as the secondary antibody. Hematoxylin was used as a counterstain. Positive staining on the human tonsil, performed on a Leica Biosystems BOND™ RX instrument.
    The section was incubated with ab227668 for 10 mins at room temperature.

  • Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP199] (ab227668), expandable thumbnail

    Flow Cytometry (Intracellular) - Anti-CD21 antibody [SP199] (ab227668)

    Flow cytometric analysis of Raji (human Burkitt's lymphoma cell line) cell line labeling CD21 with ab227668 at 1/100 (green) compared with a rabbit isotype control (blue).

  • Western blot - Anti-CD21 antibody [SP199] (ab227668), expandable thumbnail

    Western blot - Anti-CD21 antibody [SP199] (ab227668)

    All lanes: Western blot - Anti-CD21 antibody [SP199] (ab227668) at 1/150 dilution

    All lanes: Daudi (human Burkitt's lymphoma cell line) cell lysate

    Developed using the ECL technique.

    Predicted band size: 113 kDa

  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (ab227668), expandable thumbnail

    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (ab227668)

    Formalin-fixed, paraffin-embedded human tonsil tissue stained for CD21 with ab227668 at 1/100 dilution in immunohistochemical analysis.

  • Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (ab227668), expandable thumbnail

    Immunohistochemistry (Formalin/PFA-fixed paraffin-embedded sections) - Anti-CD21 antibody [SP199] (ab227668)

    Formalin-fixed, paraffin-embedded human reactive lymph node tissue stained for CD21 with ab227668 at 1/100 dilution in immunohistochemical analysis.

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Product protocols

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