Platelet-derived growth factor (PDGF) was discovered as a major mitogenic factor present in serum but absent from plasma. It was found to be secreted from the α-granules of platelets activated during the coagulation of blood to form serum.
Specifications and Use of R&D PDGF
Source of of R&D PDGF
• A DNA sequence encoding the 109 amino acid residue mature human PDGF-B chain protein sequence (C-terminally processed form that ends with threonine residue 190 in the precursor sequence) (Johnsson, A. et al., 1984, EMBO J. 3:921) was expressed in E. coli.
Molecular Mass of Recmbinant PDGF-BB
• The disulfide-linked homodimeric recombinant human PDGF-BB, containing two 109 amino acid residue B chain monomers, has a molecular mass of approximately 25 kDa.
Purity of R&D PDGF
• > 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 PDGF
• 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 1.5 - 6 ng/mL in a fluorometric assay using the redox sensitive dye, Resazurin (R&D Systems, Catalog # AR002).
Formulation of Recombinant PDGF-BB
• Lyophilized from a 0.2 μm filtered solution in 30% acetonitrile and 0.1% TFA.
Reconstitution of R&D PDGF
• It is recommended that sterile 4 mM HCl 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 of the cytokine.
Storage of R&D PDGF
• 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.