Hu Recom SCF, 1000 µg

From STEMCELL Technologies, this research-use cytokine is Human Recombinant SCF, an E. coli-expressed early-acting cytokine that plays a pivotal role in the regulation of embryonic and adult hematopoiesis. It promotes cell survival, proliferation, differentiation, adhesion, and functional activation of cells at multiple levels of the hematopoietic hierarchy. Together with cytokines such as thrombopoietin and Flt3/Flk-2 Ligand, it is commonly used to promote expansion of primitive hematopoietic stem cells and multi-potent progenitor cells in culture. In synergy with growth factors including IL-2, IL-3, IL-6, IL-7, G-CSF, and erythropoietin, SCF increases proliferation and differentiation of myeloid and erythroid progenitor cells and a subset of lymphoid progenitor cells, and serves as a primary growth and activation factor for mast cells and eosinophils. Alternative names include Kit ligand, Mast cell growth factor, Steel factor, and Stem cell factor.

SCF exists in two biologically active splice forms (a soluble and a transmembrane isoform) and signals through the c-Kit tyrosine kinase receptor (CD117) to activate PI3K, JAK/STAT, and MAPK pathways, with additional reported roles in pigmentation, fertility, vasculogenesis, gut motility, and migration of neuronal stem and progenitor cells to injury sites in the brain. The protein is lyophilized from a sterile-filtered aqueous solution containing sodium phosphate and sodium chloride at pH 7.5, has a predicted molecular mass of 18.6 kDa, and the human sequence is catalogued under accession P21583. According to the manufacturer's specifications, the specific activity is ≥ 6.6 x 10^4 units/mg (EC50 ≤ 15 ng/mL) as determined by a cell proliferation assay using TF-1 cells, and biological activity was demonstrated in a representative assay with an EC50 of 1 ng/mL. The product is reported to be weakly active on mouse cells.

For preparation, the vial should be centrifuged before opening and reconstituted in sterile water to at least 0.1 mg/mL by pipetting the solution down the sides of the vial without vortexing. Reconstituted material may be diluted with concentrated bovine serum albumin (BSA) to a final BSA concentration of 0.1% for storage. As a general guide, do not store at 2 - 8°C for more than 1 month or at -20°C to -80°C for more than 3 months, and avoid repeated freeze-thaw cycles. Unopened material is stable as supplied for 12 months from date of receipt when stored at -20 to -80°C.