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Recombinant Human SCF Protein, Animal-Free

Bio-Techne includes R&D Systems | Catalog # BT-SCF-AFL

Intended for preclinical researchers who may transition to GMP SCF for their clinical work
Catalog #
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Key Product Details


E. coli

Accession #





Product Specifications


E. coli-derived human SCF/c-kit Ligand protein
Glu26-Ala189, with a N-terminal Met.
Produced using non-animal reagents in an animal-free laboratory.


>97%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

Endotoxin Level

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

N-terminal Sequence Analysis


Predicted Molecular Mass

19 kDa


18 kDa, under reducing conditions.


Measured in a cell proliferation assay using TF-1 human erythroleukemic cells. Kitamura, T. et al. (1989) J. Cell Physiol. 140:323.
The ED50 for this effect is 1.00-8.00 ng/mL.
The specific activity of Animal-Free™ Recombinant Human SCF/c‑kit Ligand is >1.0 x 106 units/mg, which is calibrated against the human SCF reference standard (NIBSC code: 91/682).

Scientific Data Images for Recombinant Human SCF Protein, Animal-Free

Recombinant Human SCF Protein, Animal-Free, Bioactivity.

Animal-FreeTM Recombinant Human SCF (Catalog # BT-SCF-AFL) as measured in a cell proliferation assay using TF-1 human erythroleukemic cells. The ED50 for this effect is 1.00-8.00 ng/mL.Two independent lots were tested for activity and plotted on the same graph to show lot-to-lot consistency of Animal-Free SCF.

Equivalent Bioactivity of GMP, Animal-Free, and RUO grades of Recombinant Human SCF.

Equivalent bioactivity of GMP (BT-SCF-GMP), Animal-Free (Catalog # BT-SCF-AFL) and RUO (BT-SCF) grades of Recombinant Human SCF as measured in a cell proliferation assay using TF-1 human erythroleukemic cells (orange, green, red, respectively).

Animal-Free™ Recombinant Human SCF/c‑kit Ligand Protein SDS-PAGE.

2 μg/lane of Animal-Free™ Recombinant Human SCF/c‑kit Ligand Protein (Catalog # BT-SCF-AFL) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 18 kDa.

Formulation, Preparation and Storage

Formulation Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
Reconstitution Reconstitute at 500 μg/mL in PBS.
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
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.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: SCF/c-kit Ligand

Stem cell factor (SCF), also known as c-kit ligand (KL), mast cell growth factor (MGF), and steel factor (SLF), is a widely expressed 28‑40 kDa type I transmembrane glycoprotein (1). It promotes the survival, differentiation, and mobilization of multiple cell types including myeloid, erythroid, megakaryocytic, lymphoid, germ cell, and melanocyte progenitors (1‑7). SCF is a primary growth and activation factor for mast cells and eosinophils (8). Mature human SCF consists of a 189 amino acid (aa) extracellular domain (ECD), a 23 aa transmembrane segment, and a 36 aa cytoplasmic tail (9). The ECD shows both N‑linked and O-linked glycosylation (10). Proteolytic cleavage at two alternate sites in the extracellular juxtamembrane region releases a 25 kDa soluble molecule which is comparable to the only form produced by Steel-dickie mutant mice (11, 12). An alternately spliced isoform of human SCF lacks 28 aa that encompasses the primary proteolytic recognition site (13). Within the ECD of the long isoform (corresponding to this recombinant protein), human SCF shares 79%‑87% aa sequence identity with canine, feline, mouse, and rat SCF. Rat SCF is active on mouse and human cells, but human SCF is only weakly active on mouse cells (9). Noncovalent dimers of transmembrane or soluble SCF interact with the receptor tyrosine kinase SCF R/c‑kit to trigger receptor dimerization and signaling (14). 

SCF assists in the recovery of cardiac function following myocardial infarction by increasing the number of cardiomyocytes and vascular channels (15). SCF is a versatile factor in the differentiation of many specific cell types like spermatogonial stem cells (16) and megakaryocyte progenitors (17). Apart from differentiation, SCF also can maintain stemness in cells. This is the case for human bone marrow mesenchymal cells, which require SCF and hepatocyte growth factor for maintenance (18). Hematopoietic stem cells similarly require SCF from surrounding cells in their niche to maintain their stemness and their progenitors (19). SCF has also improved protocols for continuous generation of cells in culture systems, like granulocytes and macrophages (20).   

For treatment of graft versus host disease, SCF is used in combination with other cytokines to generate myeloid-derived suppressor cells from human umbilical cord blood (21). SCF is also used to generate T cells for cell-based therapies, drug screening and disease modeling (22). In regenerative studies, SCF is applied in wound healing hydrogel as a means of increasing its adhesion strength and tissue regeneration (23).


  1. Ashman, L.K. (1999) Int. J. Biochem. Cell Biol. 31:1037. 
  2. Sette, C. et al. (2000) Int. J. Dev. Biol. 44:599. 
  3. Yoshida, H. et al. (2001) J. Invest. Dermatol. Symp. Proc. 6:1. 
  4. Erlandsson, A. et al. (2004) Exp. Cell Res. 301:201. 
  5. Kapur, R. et al. (2002) Blood 100:1287. 
  6. Wang, C.H. et al. (2007) Arterioscler. Thromb. Vasc. Biol. 27:540. 
  7. Bashamboo, A. et al. (2006) J. Cell Sci. 119:3039. 
  8. Reber, L. et al. (2006) Eur. J. Pharmacol. 533:327.
  9. Martin, F.H. et al. (1990) Cell 63:203.
  10. Arakawa, T. et al. (1991) J. Biol. Chem. 266:18942.
  11. Majumdar, M.K. et al. (1994) J. Biol. Chem. 269:1237.
  12. Brannan, C.I. et al. (1991) Proc. Natl. Acad. Sci. 88:4671.
  13. Anderson, D.M. et al. (1991) Cell Growth Differ. 2:373.
  14. Lemmon, M.A. et al. (1997) J. Biol. Chem. 272:6311.
  15. Kanellakis, P. et al. (2006) Cardiovasc. Res. 70:117.
  16. Nasimi, M. et al. (2021) Reprod Sci. 28:963.
  17. Krisch, L. et al. (2021) Int. J. Mol. Sci. 22:8224.
  18. Cao, Z. et al. (2020) Stem Cell Res Ther. 11:1.
  19. Comazzetto, S. et al. (2019) Cell Stem Cell. 24:477.
  20. Bernecker, C. et al. (2019) Stem Cells Dev. 28:1540.
  21. Park, M.Y. et al. (2019) Front Immunol. 10:1.
  22. Netsrithong, R. et al. (2020) Stem Cell Res Ther. 11:1.
  23. Zhang, Li. et al. (2021) Journal Mater Chem B. 29:5887.

Long Name

Stem Cell Factor

Alternate Names

c-kit Ligand, DCUA, DFNA69, FPH2, FPHH, KITLG, KL-1, MGF, SHEP7, SLF

Entrez Gene IDs

4254 (Human); 17311 (Mouse); 60427 (Rat); 403507 (Canine); 493937 (Feline)

Gene Symbol



Additional SCF/c-kit Ligand Products

Product Documents for Recombinant Human SCF Protein, Animal-Free

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Note: Certificate of Analysis not available for kit components.

Manufacturing Specifications

Animal-Free Manufacturing Conditions
Our dedicated controlled-access animal-free laboratories ensure that at no point in production are the products exposed to potential contamination by animal components or byproducts. Every stage of manufacturing is conducted in compliance with R&D Systems' stringent Standard Operating Procedures (SOPs). Production and purification procedures use equipment and media that are confirmed animal-free.  


  • All molecular biology procedures use animal-free media and dedicated labware.
  • Dedicated fermentors are utilized in committed animal-free areas.


  • Protein purification columns are animal-free.
  • Bulk proteins are filtered using animal-free filters.
  • Purified proteins are stored in animal-free containers in a dedicated cold storage room.

    Quality Assurance

    • Low Endotoxin Level.
    • No impairment of biological activity.
    • High quality product obtained under stringent conditions.
    • For ex vivo research or bioproduction, additional documentation can be provided.

    Please read our complete Animal-Free Statement

    Product Specific Notices for Recombinant Human SCF Protein, Animal-Free

    For research use only