Specifications and Use of R&D FGF
R&D FGF Source
• A DNA sequence corresponding to the mature human FGF basic protein sequence (Sommer, A. et al., 1987, BBRC 144:543 - 550) was expressed in E. coli.
• Note: This is one of multiple forms available for this protein. Check R&D Systems' website, www.RnDSystems.com, for a complete listing of the variants.
R&D Recombinant FGF Molecular Mass
• The 157 amino acid residue recombinant protein has a molecular mass of 17.4 kDa.
Purity of R&D FGF
• > 97%, as determined by SDS-PAGE and visualized by silver stain.
Endotoxin Level of R&D FGF
• < 1.0 EU per 1 μg of the cytokine as determined by the LAL method.
R&D FGF basic Activity
• Measured by its ability to stimulate proliferation of NR6R-3T3 fibroblasts (Raines, E.W. et al., 1985, Methods Enzym. 109:749).
• The ED50 for this effect is typically 0.5 - 2.5 ng/mL in a fluorometric assay using the redox sensitive dye, Resazurin (R&D Systems, Catalog # AR002).
Formulation of R&D FGF
• Supplied as a 0.2 μm filtered solution in 20 mM Tris-HCl and 1 M NaCl (pH 7.0) containing 50 μg of bovine serum albumin per 1 μg of the cytokine.
• Centrifuge the vial before opening to recover entire contents of the vial. Due to possible sublimation during storage, the buffer volume may decrease over time, however, the product is sold by mass and the amount of protein will remain constant. To ensure quantitative recovery, we suggest the stock solution be made in the original vial.
R&D FGF Storage
• Samples are stable for up to twelve months at -20° C to -70° C in a manual defrost freezer.
• Upon thawing, 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.