E. coli-derived human SCF/c-kit Ligand protein Glu26-Ala189, with an N-terminal Met. Produced using non-animal reagents in an animal-free laboratory. Manufactured and tested under cGMP guidelines.
>97%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining. The result from mass spectrometry confirms the major peak corresponds to SCF/c-kit ligand. See the CofA for additional information
<0.10 EU per 1 μg of the protein by the LAL method.
N-terminal sequence Analysis
Predicted Molecular Mass
17-18 kDa, 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 1‑5 ng/mL.The specific activity of recombinant human SCF is >1.0 x 106 units/mg, which is calibrated against the human SCF reference standard (NIBSC code: 91/682).
Recombinant Human SCF GMP Protein, CF Scientific Data Examples
Recombinant Human SCF GMP Protein Bioactivity
GMP-grade Recombinant Human SCF (Catalog # 255B-GMP) stimulates cell proliferation of the TF‑1 human erythroleukemic cell line. The ED50 for this effect is 1-5 ng/mL. Four independent lots were tested for activity and plotted on the same graph to show lot-to-lot consistency of GMP SCF.
Equivalent Bioactivity of GMP and Animal-Free grades of Recombinant Human SCF
Equivalent bioactivity of GMP (Catalog # 255B-GMP) and Animal-Free (AFL255) grades of Recombinant Human SCF as measured in cell proliferation assay (orange and green respectively).
Recombinant Human SCF GMP Protein SDS-PAGE
2 μg/lane of GMP-grade Recombinant Human SCF (Catalog # 255B-GMP) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing R band at 18 kDa and NR band at 16 kDa, respectively.
Formulation, Preparation and Storage
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
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
Lyophilized from a 0.2 μm filtered solution in PBS.
Reconstitute at 100 μg/mL in PBS.
The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage:
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
A minimum of 12 months when stored at ≤ -20 °C as supplied. Refer to lot specific COA for the Use by Date.
1 month, 2 to 8 °C under sterile conditions after reconstitution.
3 months, ≤ -20 °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).
Ashman, L.K. (1999) Int. J. Biochem. Cell Biol. 31:1037.
Sette, C. et al. (2000) Int. J. Dev. Biol. 44:599.
Yoshida, H. et al. (2001) J. Invest. Dermatol. Symp. Proc. 6:1.
Erlandsson, A. et al. (2004) Exp. Cell Res. 301:201.
Kapur, R. et al. (2002) Blood 100:1287.
Wang, C.-H. et al. (2007) Arterioscler. Thromb. Vasc. Biol. 27:540.
Bashamboo, A. et al. (2006) J. Cell Sci. 119:3039.
Reber, L. et al. (2006) Eur. J. Pharmacol. 533:327.
Martin, F.H. et al. (1990) Cell 63:203.
Arakawa, T. et al. (1991) J. Biol. Chem. 266:18942.
Majumdar, M.K. et al. (1994) J. Biol. Chem. 269:1237.
Brannan, C.I. et al. (1991) Proc. Natl. Acad. Sci. 88:4671.
Anderson, D.M. et al. (1991) Cell Growth Differ. 2:373.
Lemmon, M.A. et al. (1997) J. Biol. Chem. 272:6311.
Kanellakis, P. et al. (2006) Cardiovasc. Res. 70:117.
GMP Proteins R&D Systems, a Bio-Techne Brand's GMP proteins are produced according to relevant sections of the following documents: WHO TRS, No. 822, 1992 Annex 1, Good Manufacturing Practices for Biological Products; USP Chapter 1043, Ancillary Materials for Cell, Gene and Tissue-Engineered Products and USP Chapter 92, Growth Factors and Cytokines Used in Cell Therapy Manufacturing.
R&D Systems' quality focus includes:
Manufactured and tested under an ISO 9001:2015 and ISO 13485:2016 certified quality system
Documented processes and QA control of documentation and process changes
Personnel training programs
Raw material testing and vendor qualification/monitoring
Fully validated equipment, processes and test methods
Equipment calibration schedules using a computerized calibration program
Facility maintenance, safety programs and pest control
Material review process for variances
Monitoring of stability over product shelf-life
R&D Systems strives to provide our customers with the analytical characteristics of each product so that customers may determine whether our products are appropriate for their research. The Certificate of Analysis provided contains the following lot specific information:
N-terminal amino acid analysis, SDS-PAGE analysis, mass spectrometry, and endotoxin level (as determined by LAL assay) performed on each bulk QC lot, not on individual bottlings of each QC lot
Post-bottling lot-specific bioassay results (compliance with an established range) and results of microbial testing according to USP
Host Cell Protein testing performed by ELISA
Mycoplasma testing by ribosomal RNA hybridization assay
Additional testing and documentation requested by the customer can be arranged at an additional cost.
Production records and facilities are available for examination by appropriate personnel on-site at R&D Systems in Minneapolis, Minnesota USA.
R&D Systems sells GMP grade products for preclinical or clinical ex vivo use. They are not for in vivo use. Please read the following End User Terms prior to using this product.
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.
Low Endotoxin Level.
No impairment of biological activity.
High quality product obtained under stringent conditions.
The End User is aware that R&D Systems, Inc. sells GMP products for preclinical or clinical ex vivo use and not for in vivo use. The End User further agrees, as a condition of the sale of R&D Systems' GMP products that: a) the End User will not use this GMP Product in any procedure wherein the product may be directly or indirectly administered to humans, unless the End User has obtained, or prior to their use will have obtained, an Investigational New Drug (IND) exemption from the FDA and will use the product only in accordance with the protocols of such IND and of the Institutional Review Board overseeing the proposed research, or b) the End User will use the products outside of the United States in accordance with the protocols of research approved by the Institutional Review Board or authorized ethics committee and regulatory agencies to which the End User is subject to in their territory.
TERMS AND CONDITIONS
The following limitation applies to R&D Systems' warranty and liability for damages: All products are warranted to meet R&D Systems' published specifications when used under normal laboratory conditions.
R&D SYSTEMS DOES NOT MAKE ANY OTHER WARRANTY OR REPRESENTATION WHATSOEVER, WHETHER EXPRESS OR IMPLIED, WITH RESPECT TO ITS PRODUCTS. IN PARTICULAR, R&D SYSTEMS DOES NOT MAKE ANY WARRANTY OF SUITABILITY, NONINFRINGEMENT, MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE.
NOTWITHSTANDING ANY OTHER PROVISIONS OF THESE TERMS AND/OR ANY OTHER AGREEMENT BETWEEN R&D SYSTEMS AND PURCHASER FOR THE PURCHASE OF THE PRODUCTS, R&D SYSTEMS' TOTAL LIABILITY TO PURCHASER ARISING FROM OR IN RELATION TO THESE TERMS, AN AGREEMENT BETWEEN THE PARTIES OR THE PRODUCTS, WHETHER ARISING IN CONTRACT, TORT OR OTHERWISE SHALL BE LIMITED TO THE TOTAL AMOUNT PAID BY PURCHASER TO R&D SYSTEMS FOR THE APPLICABLE PRODUCTS. IN NO EVENT WILL R&D SYSTEMS BE LIABLE FOR THE COST OF PROCUREMENT OF SUBSTITUTE GOODS.
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments are available to quote. ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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