Granulocyte Colony Stimulating Factor (G-CSF)

Four distinct colony-stimulating factors (CSFs) promoting survival, proliferation and differentiation of bone marrow precursor cells have been well characterized: ranulocyte/macrophage-CSF (GM-CSF), granulocyte-CSF (G-CSF), macrophage-CSF (M-CSF), and interleukin-3 (IL-3, Multi-CSF).1, 2 G-CSF and M-CSF are lineage-restricted hematopoietic growth factors, stimulating final mitotic divisions and terminal cellular maturation of partially differentiated hematopoietic progenitors. In humans, two distinct cDNA clones for G-CSF, encoding 207 and 204 amino acid precursor proteins, have been isolated.3, 4 Both proteins have a 30 amino acid signal peptide and identical amino acid sequences except for a three amino acid insertion (deletion) at the 35th amino acid residue from the N-terminus of the mature protein. Natural G-CSF is a glycoprotein of 177 amino acids and a molecular mass of ~18.8kD. Human and mouse G-CSF share ~73 % amino acid sequence homology and show biological crossreactivity. Granulocyte colony stimulating factor is produced by: macrophages activated by endotoxin (LPS), monocytes activated by TNFa with INFg, fibroblasts and endothelial cells activated by IL-1 or TNF-a, and bone marrow stromal cells activated by IL-1 or LPS.3, 4 In addition, various carcinoma cell lines and myeloblastic leukemia cells can express G-CSF constitutively. G-CSF stimulates granulocyte colony formation, activates neutrophils and other mature granulocytes, and promotes differentiation of certain myeloid leukemic cells. G-CSF acts on mature neutrophils to enhance their survival and to stimulate their tumorcidal activity. It will also synergize with IL-3 and shorten the G0 period of early hematopoietic progenitors. G-CSF has important roles in defense against infection, in inflammation and repair processes, and in maintenance of steady state hematopoiesis. Applications: Suitable for use in ELISA, Western Blot and neutralization. Other applications not tested. Recommended Dilution: Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4 degrees C for short-term only. For long-term storage and to avoid repeated freezing and thawing, add sterile glycerol (40-50%), aliquot and store at -20 degrees C. Aliquots are stable for at least 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.