Granulocyte colony stimulating factor (G-CSF) is a pleiotropic cytokine. It is mainly produced by monocytes and macrophages upon activation by endotoxin, TNF-alpha and IFN-gamma. Besides, many other cell types can secreted this protein after LPS, IL-1 or TNF-alpha activation, which are fibroblasts, endothelial cells, astrocytes and bone marrow stromal cells. Various carcinoma cell lines and myeloblastic leukemia cells can express G-CSF constitutively. G-CSF is cytokine that acts in hematopoiesis by controlling the production, differentiation, and function of 2 related white cell populations of the blood, the granulocytes and the monocytes-macrophages. In addition it may function in some adhesion or recognition events at the cell surface.
In humans, two distinct cDNA clones for G-CSF, encoding 207 and 204 amino acid (a.a.) precursor proteins, have been isolated. Both proteins have a 30 a.a. signal peptide and have identical amino acid sequences except for a three a.a. insertion (deletion) at the 35th a.a. residue from the N-terminus of the mature protein. Human G-CSF is 73 % identical at the amino acid level to murine G-CSF and the two proteins show species cross-reactivity.
Source
Escherichia coli.
Molecular Weight
Approximately 18.7 kDa, a single non-glycosylated polypeptide chain containing 174 amino acids.
Biological Activity
Fully biologically active when compared to standard. The ED50 as determined by a cell proliferation assay using murine NFS-60 cells is less than 0.1 ng/ml, corresponding to a specific activity of > 1.0 × 107 IU/mg.
Appearance
Sterile filtered white lyophilized (freeze-dried) powder.
Formulation
Lyophilized from a 0.2 um filtered concentrated solution in 10mM sodium acetate buffer, containing 5 % trehalose, pH 4.0.
Endotoxin
Less than 1 EU/ug of rHuG-CSF as determined by LAL method.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1 % BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 °C. Further dilutions should be made in appropriate buffered solutions.
Stability and 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.
