• Species Reactivity

  Human

• Specificity

  Detects human TfR in direct ELISAs.

• Source

  Monoclonal Mouse IgG    ₁ Clone # 29806

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  Human TfR

• 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

• Flow Cytometry

  2.5 µg/10    ⁶ cells

  U937 human cell line

• 
  

• 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.

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: TfR (Transferrin R)

The Transferrin Receptor (TfR or TfR-1, designated CD71) is a type 2 transmembrane glycoprotein expressed on erythroid progenitors, muscle cells and proliferating cells as a 188 kDa disulfide-linked homodimer of 95 kDa monomers (1‑4). As the major mediator of cellular iron uptake, it binds and internalizes diferric transferrin, allowing iron release at the low pH of the endosome (2, 5). The human TfR cDNA encodes 760 amino acids (aa) including a 67 aa N-terminal intracellular domain, a 21 aa transmembrane domain, and a 672 aa extracellular domain (ECD) with helical, peptidase (nonfunctional), and ligand binding domains, including an RGD potential integrin binding site (5). Human TfR ECD shares 75‑80% aa identity with mouse, rat, feline, canine, equine, porcine and bovine TfR. A 679 aa alternately spliced form begins at aa 82 and is presumably secreted, while in an 804 aa form, 44 aa are inserted at aa 518 within the peptidase region (6). Most soluble TfR (sTfR) arises from trypsin proteolysis at aa 100, producing the circulating form of TfR (3). sTfR concentration in plasma or serum is proportional to total TfR and can be increased by iron deficiency (3). Erythroid progenitors, which use iron for hemoglobin synthesis, normally account for the bulk of total body TfR production (3). Since rapidly growing cells require iron to replicate DNA, cancer cells can express up to 5-fold more TfR than quiescent cells in the surrounding tissue (2, 4). Antibody targeting of TfR can inhibit tumor cell proliferation and induce apoptosis (2, 4). The hereditary hemochromatosis protein HFE competes with diferric transferrin for binding to TfR, and targets TfR for degradation rather than recycling (2, 5). TfR has been reported to have ferritin-independent functions in T cell development, immunological synapse formation and galectin-3-mediated cell death, and to be a cell entry receptor for New World hemorrhagic fever arenaviruses (2, 4, 7).

• References:

1. Schneider, C. et al. (1984) Nature 311:675.

2. Daniels, T.R. et al. (2006) Clin. Immunol. 121:144.

3. Skikne, B.S. (2008) Am. J. Hematol. 83:872.

4. Macedo, M.F. and M. deSousa (2008) Inflamm. Allergy Drug Targets 7:41.

5. Aisen, P. (2004) Int. J. Biochem. Cell Biol. 36:2137.

6. Entrez protein Accession # EAW53671, EAW53672.

7. Radoshitzky, S.R. et al. (2007) Nature 446:92.

• Long Name:

  Transferrin Receptor

• Entrez Gene IDs:

  7037 (Human); 22042 (Mouse); 64678 (Rat)

• Alternate Names:

  CD71 antigen; CD71; CD71TRFR; p90; T9; TfR (Transferrin R); TfR (TransferrinR); TfR; TFR1; TFRC; TR; transferrin receptor (p90, CD71); transferrin receptor protein 1; TRFR