Recombinant Anti-CD21 antibody [SP199] (ab227668)


  • Product name

    Anti-CD21 antibody [SP199]
    See all CD21 primary antibodies
  • Description

    Rabbit monoclonal [SP199] to CD21
  • Host species

  • Tested applications

    Suitable for: WB, Flow Cyt, IHC-Pmore details
  • Species reactivity

    Reacts with: Human
    Predicted to work with: Mouse
  • Immunogen

    Synthetic peptide within Human CD21 aa 1000 to the C-terminus (C terminal). The exact sequence is proprietary.
    Database link: P20023

  • Positive control

    • WB: Daudi cell lysate. IHC-P: Human tonsil and reactive lymph node tissue. FC: Raji cells.


  • Form

  • Storage instructions

    Shipped at 4°C. Store at +4°C short term (1-2 weeks). Upon delivery aliquot. Store at -20°C long term. Avoid freeze / thaw cycle.
  • Storage buffer

    pH: 7.6
    Preservative: 0.1% Sodium azide
    Constituents: PBS, 1% BSA
  • Concentration information loading...
  • Purity

    Protein A/G purified
  • Purification notes

    Purified from TCS by protein A/G.
  • Clonality

  • Clone number

  • Isotype

  • Research areas


Our Abpromise guarantee covers the use of ab227668 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 1/150. Predicted molecular weight: 113 kDa.
Flow Cyt 1/20 - 1/100.
IHC-P 1/100.

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


  • Function

    Receptor for complement C3Dd, for the Epstein-Barr virus on human B-cells and T-cells and for HNRPU. Participates in B lymphocytes activation.
  • Tissue specificity

    Mature B-lymphocytes, T-lymphocytes, pharyngeal epithelial cells, astrocytes and follicular dendritic cells of the spleen.
  • Involvement in disease

    Genetic variations in CR2 are associated with susceptibility to systemic lupus erythematosus type 9 (SLEB9) [MIM:610927]. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a complex genetic basis. SLE is an inflammatory, and often febrile multisystemic disorder of connective tissue characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is thought to represent a failure of the regulatory mechanisms of the autoimmune system.
  • Sequence similarities

    Belongs to the receptors of complement activation (RCA) family.
    Contains 15 Sushi (CCP/SCR) domains.
  • Cellular localization

  • Information by UniProt
  • Database links

  • Alternative names

    • C3DR antibody
    • CD 21 antibody
    • CD21 antibody
    • Complement C3d receptor 2 antibody
    • Complement C3d receptor antibody
    • Complement component (3d/Epstein Barr virus) receptor 2 antibody
    • Complement receptor type 2 antibody
    • CR antibody
    • Cr2 antibody
    • CR2_HUMAN antibody
    • CVID7 antibody
    • EBV receptor antibody
    • EBV-R antibody
    • Epstein Barr virus receptor antibody
    • Epstein-Barr virus receptor antibody
    • EVBR antibody
    • SLEB9 antibody
    see all


  • 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 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, ab150077) at 1/2000 dilution was used as a secondary antibody. Isotype control - Rabbit monoclonal IgG (ab172730) (black). Unlableled control - Unlabelled cells (blue).

  • Anti-CD21 antibody [SP199] (ab227668) at 1/150 dilution + Daudi (human Burkitt's lymphoma cell line) cell lysate

    Developed using the ECL technique.

    Predicted band size: 113 kDa

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

  • 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).

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


ab227668 has not yet been referenced specifically in any publications.

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