SCF

Stem Cell Factor (SCF, also known as c-kit ligand, mast cell growth factor and steel factor) is a hematopoietic growth factor acting at the early stages of hematopoies is. SCF promotes the survival, proliferation, and differentiation of both myeloid and lymphoid hematopoietic progenitors in bone marrow culture. It also stimulates the growth and activation of mast cells and eosinophils. SCF has been shown to act synergistically with other growth factors, such as GM-CSF, G-CSF, IL-7 and EPO. Human SCF shows low activity on murine cells, while murine and rat SCF are fully active on human cells.

Produced in the endosperm tissue of barley grain (Hordeum vulgare).

PBS pH 7.2, sterile filtered through 0.2 µm filter.

Greater than 95% by SDS-PAGE gel analysis.

Note: Always centrifuge the vial before opening. It is recommended to reconstitute the lyophilized protein in sterile buffered saline to a concentration of no less than 100 µg/ml. For long term storage of the reconstituted solution it is recommended to add a carrier protein (0.1% HSA or BSA).

The lyophilized protein, though stable at room temperature for few weeks, is best stored at -20°C. Reconstituted protein should be used immediately or stored in working aliquots at -20°C. Avoid repeated freeze-thaw cycles.

The bioactivity of ISOkine® recombinant human SCF is assayed by measuring its dose dependent effect on proliferation of TF-1 cells.

The ED50 for this effect is between 2 -10 ng/ml corresponding to specific activity of 1 –5 x 10e5 U/mg.

We recommend that the optimal concentration for each specific application be determined by an initial dose-response assay. Each batch of ISOkine® growth factor is tested for bioactivity and verified to have comparable activity to a commercial source.

Endotoxin level is less than 0.005ng per µg of IISOkine® product (0.05EU/µg).

Purified ISOkine® product carries no pyrogenic or pro-inflammatory contaminants, as assayed with monocyte activation test using Human 10-plex Cytokine Assay measuring IL-6, TNF-alpha and IL-1 beta induction. ** Ref. The Blood Bank, University Hospital of Iceland, Reykjavik, Iceland

Recombinant human SCF contains 165 amino acids and a 16 a.a. histidine-based tag for a total length of 181 a.a. and has a predicted molecular mass of 20.7 kDa including his-tag. As a result of glycosylation, the recombinant protein migrates with an apparent molecular mass of 22-24 kDa in SDS-PAGE