M-CSF is produced by monocytes, granulocytes, endothelial cells, and fibroblasts. After cell activation, B cells and T cells and also a number of tumor cell lines are capable also of synthesizing this factor. M-CSF has been found to be synthesized by uterine epithelial cells in vivo. The M-CSF receptor is identical with the proto-oncogene fms. It has been renamed CD115. The receptor is a transmembrane protein with an extracellular ligand-binding domain of 512 amino acids, an intramembrane domain of 25 amino acids, and a cytoplasmic domain of 435 amino acids encoding a tyrosine kinase. Human M-CSF is active in mouse and rat cells. The murine factor is active in rat cells but inactive in human cells. M-CSF is a specific factor in that the proliferation inducing activity is more or less restricted to the macrophage lineage. M-CSF is a potent stimulator of functional activities of monocytes. Recombinant Human M-CSF is expressed in human 293 cells and has an apparent molecular mass of 35 to 40 kDa due to glycosylation.
<1 EU/µg of recombinant protein as determined by the LAL method
Biological Activity Comment
The EC(50) as determined by the dose-dependent stimulation of the proliferation of murine M-NFS-60 cells (Mouse Myeloid Leukemia indicator cell line) was found to be ≤ 4 ng/mL.
Weight
35 and 40 kDa, homodimer, glycosylated
Description
A quick spin of the vial followed by reconstitution in sterile 1xPBS containing 0.1% endotoxin-free recombinant human serum albumin (HSA).
Format
Lyophilized Powder1x PBS
Purity
>95% as determined by SDS-PAGE
Storage
The lyophilized protein is stable for at least one year from date of receipt at -70°C. Upon reconstitution, this cytokine can be stored in working aliquots at 2° - 8°C for one month, or at -20°C for six months. Avoid repeated freeze/thaw cycles.