GM-CSF was initially characterized as a factor that can support the in vitro colony formation of granulocyte-macrophage progenitors. It is also a growth factor for erythroid, megakaryocyte, and eosinophil progenitors. GM-CSF is produced by a number of different cell types in response to cytokine or inflammatory stimuli.
Specifications and Use for R&D GM-CSF
Source of R&D GM-CSF
• A DNA sequence encoding the mature human GM-CSF protein (Ala 18 - Glu 144; Accession # CAA26822) was expressed in E. coli.
• The 127 amino acid residue recombinant protein has a predicted molecular mass of approximately 14 kDa.
Purity of R&D GM-CSF
• > 97%, as determined by SDS-PAGE and visualized by silver stain.
• < 1.0 EU per 1 μg of the cytokine as determined by the LAL method.
Activity of R&D GM-CSF
• Measured in a cell proliferation assay using the factor-dependent cell line, TF-1 (Kitamura, T. et al., 1989, J. Cell Physiol. 140:323 - 343).
• The ED50 for this effect is typically 6 - 30 pg/mL. The cell number is assessed in a fluorometric assay using the redox sensitive dye, Resazurin (R&D Systems, Catalog # AR002).
Formulation of R&D GM-CSF
• Lyophilized from a 0.2 μm filtered solution in PBS containing 50 μg of bovine serum albumin per 1 μg of cytokine.
Reconstitution of R&D GM-CSF
• It is recommended that sterile phosphate-buffered saline containing at least 0.1% human serum albumin or bovine serum albumin be added to the vial to prepare a stock solution of no less than 10 μg/mL.
Storage of R&D GM-CSF
• Lyophilized samples are stable for up to twelve months from date of receipt at -20° C to -70° C.
• Upon reconstitution, this cytokine can be stored under sterile conditions at 2° - 8° C for one month or at -20° C to -70° C in a manual defrost freezer for three months without detectable loss of activity.
• Avoid repeated freeze-thaw cycles.