• Species Reactivity

  Human

• Specificity

  Detects human CD21 in direct ELISAs and Western blots.

• Source

  Monoclonal Mouse IgG    ₁ Clone # 544408

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  Chinese hamster ovary cell line CHO-derived recombinant human CD21    
  Ile21-Arg971    
  Accession # P20023

• Formulation

  Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied as a 0.2 µm filtered solution in PBS.

• Label

  Unconjugated

Applications

• Recommended    
  Concentration

  Sample

• Western Blot

  2 µg/mL

  See below

• 
  

• Flow Cytometry

  0.25 µg/10    ⁶ cells

  See below

• 
  

• CyTOF-ready

  Ready to be labeled using established conjugation methods. No BSA or other carrier proteins that could interfere with conjugation.

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Data Examples

Preparation and Storage

• Reconstitution

  Reconstitute at 0.5 mg/mL in sterile PBS.

• Shipping

  The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. *Small pack size (SP) is shipped with polar packs. Upon receipt, store it immediately at -20 to -70 °C

• Stability & Storage

  Use a manual defrost freezer and avoid repeated freeze-thaw cycles.    

• 12 months from date of receipt, -20 to -70 °C as supplied.

• 1 month, 2 to 8 °C under sterile conditions after reconstitution.

• 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: CD21

CD21 (also called EBV receptor or CR2) is a 145 kDa member of the RCA (receptors of complement activation) family of proteins. It is expressed on T cells, B cells, and follicular dendritic cells. On the B cell surface, it combines with the BCR and CD19 to form a B cell activating complex. Mature human CD21 is 1013 amino acids (aa) in length. It is a type I transmembrane (TM) protein that contains a 951 aa extracellular domain (ECD) (aa 21-971) and a short 34 aa cytoplasmic tail. The ECD exhibits fifteen 60 aa SUSHI repeats. Soluble CD21 can be generated by cleavage near the TM domain. One potential splice variant shows a deletion of aa 847‑908, while another shows an insertion of 59 aa after Lys659. The ECD of human CD21 shares 71% aa identity with mouse CD21 ECD.

• Entrez Gene IDs:

  1380 (Human); 12902 (Mouse); 289395 (Rat)

• Alternate Names:

  C3DR; C3DRSLEB9; CD21 antigen; CD21; Complement C3d receptor; complement component (3d/Epstein Barr virus) receptor 2; complement receptor type 2; CR2; EBV receptor; Epstein-Barr virus receptor