• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured in a cell proliferation assay using TF?1 human erythroleukemic cells. Kitamura, T.     et al. (1989) J. Cell Physiol.     140:323. The ED    ₅₀ for this effect is 0.4-2 ng/mL.

• Source

  Mouse myeloma cell line, NS0-derived Ala41-Arg206

• Accession #

• N-terminal Sequence    
  Analysis

  Ala41

• Predicted Molecular Mass

  18.4 kDa

• SDS-PAGE

  36-38 kDa, reducing conditions

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: Erythropoietin

Erythropoietin (Epo) is a 34 kDa glycoprotein hormone in the type I cytokine family and is related to thrombopoietin (1). Its three N-glycosylation sites, four alpha helices, and N- to C-terminal disulfide bond are conserved across species (2). Glycosylation of Epo is required for biological activities in vivo (3). Mature canine Epo shares 95% amino acid sequence identity with feline Epo and 80% - 89% with bovine, equine, human, mouse, ovine, porcine, and rat Epo. Epo is primarily produced in the kidney by a population of fibroblast-like cortical interstitial cells adjacent to the proximal tubules (4). It is also produced in much lower, but functionally significant amounts by fetal hepatocytes and in adult liver and brain (5 - 7). Epo promotes erythrocyte formation by preventing the apoptosis of early erythroid precursors which express the Epo receptor (Epo R) (7, 8). Epo R has also been described in brain, retina, heart, skeletal muscle, kidney, endothelial cells, and a variety of tumor cells (6, 7, 9, 10). Ligand induced dimerization of Epo R triggers JAK2-mediated signaling pathways followed by receptor/ligand endocytosis and degradation (1, 11). Rapid regulation of circulating Epo allows tight control of erythrocyte production and hemoglobin concentrations. Anemia or other causes of low tissue oxygen tension induce Epo production by stabilizing the hypoxia-induceable transcription factors HIF-1 alpha and HIF-2 alpha (1, 5). Epo additionally plays a tissue-protective role in ischemia by blocking apoptosis and inducing angiogenesis (6, 7, 12).

• References:

1. Koury, M. J. (2005) Exp. Hematol. 33:1263.

2. Wen, D. et al. (1993) Blood 82:1507.

3. Tsuda E., et al. (1990) Eur. J. Biochem. 188:405.

4. Lacombe, C. et al. (1988) J. Clin. Invest. 81:620.

5. Eckardt, K. U. and A. Kurtz (2005) Eur. J. Clin. Invest. 35 Suppl. 3:13.

6. Sharples, E. J. et al. (2006) Curr. Opin. Pharmacol. 6:184.

7. Rossert, J. and K. Eckardt (2005) Nephrol. Dial. Transplant 20:1025.

8. Koury, M.J. and M.C. Bondurant (1990) Science 248:378.

9. Acs, G. et al. (2001) Cancer Res. 61:3561.

10. Hardee, M.E. et al. (2006) Clin. Cancer Res. 12:332.

11. Verdier, F. et al. (2000) J. Biol. Chem. 275:18375.

12. Kertesz, N. et al. (2004) Dev. Biol. 276:101.

• Entrez Gene IDs:

  2056 (Human); 13856 (Mouse); 24335 (Rat)

• Alternate Names:

  EP; EPO; epoetin; Erythropoietin; MGC138142; MVCD2