Qk025 human FGF2 (bFGF)

Fibroblast growth factor 2 (FGF2) or basic FGF has a broad range of physiological roles including regulation of cell proliferation and differentiation. FGF2 is used to support the maintenance of human embryonic stem cells and proliferation and differentiation of induced pluripotent and mesenchymal stem cells.

1. Ludwig, T. E. et al. Derivation of human embryonic stem cells in defined conditions. Nat. Biotechnol. 24, 185–187 (2006).
2. Ludwig, T. E. et al. Feeder-independent culture of human embryonic stem cells. Nat. Methods 3, 637–646 (2006).
3. Chen, G., Gulbranson, D. R., Yu, P., Hou, Z. & Thomson, J. A. Thermal stability of fibroblast growth factor protein is a determinant factor in regulating self-renewal, differentiation, and reprogramming in human pluripotent stem cells. Stem Cells 30, 623–30 (2012).

Basic fibroblast growth factor, bFGF, FGF-β, FGF2, Fibroblast growth factor-basic, HBGF-2

Summary: Qk025 mature domain of human FGF2 (residues 144-288, Uniprot: P09038) expressed in E.coli and purified to homogeneity

Form: protein is provided frozen in PBS (carrier protein-free) at 1 mg/ml

Molecular mass: ~17 kDa

Thaw the sample on ice, spin briefly and dilute with PBS as needed.  Our protein are supplied carrier-protein free.  If compatible with your work, add carrier protein of your choice such as BSA, HSA or gelatin to further minimise loss by adsorption.  Spin in a microfuge for 5 minutes at maximum speed, and divide the solution into suitable aliquots and store at -80°C. We recommend that single-use aliquots should be prepared to avoid freeze-thaw cycles.

Every effort is made to ensure samples are sterile however we recommend sterile filtering after dilution in media or the final working solution.

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Result: FGF2 migrates as major band at 17 kDa in non-reducing (-βME) conditions and upon reduction (+βME). The higher molecular mass band at 35 kDa is a dimer that we always see in our highly purified human FGF2, the presence of this does not affect biological activity.

Purified recombinant protein (7 µg) was resolved using 15% w/v SDS-PAGE in reduced (+β-mercaptothanol, R) and non-reduced conditions (NR) and stained with Coomassie Brilliant Blue R250.

Result: calculated molecular mass of FGF2 is 16310 Da.  Molecular mass from this analysis is 16310 Da, consistent with the calculated mass.  The calculated molecular mass of dimeric protein is 32620 Da and this is represented in the mass spec with average molecular mass 32617 Da.

MALDI mass spectrometric analysis is used to confirm the molecular mass of the intact protein and to reveal any heterogeneity that would not be evident in SDS-PAGE analysis. The results are compared with calculated mass of the protein with the assumption that all the cysteines are disulphide-linked. The different peaks represent different charge states of the protein.

Result: UV spectrum shows full recovery of protein following aliquoting and lyophilisation.

Absorbance at 280 nm: average 0.112
Recovered concentration:0.112 cm-1 x 10 /0.98 cm-1 mg ml-1 = 1.1 mg / ml
Recovery: 110% (>100% due to routine 10% over-fill of vials during aliquoting)

The sample was diluted 1:10 in 100 mM sodium phosphate pH 7.4 and the UV spectrum 340-220 nm measured in duplicate. Concentration was calculated using extinction coefficient at 280 nm

Result: Endotoxin level <0.005 EU/ug protein (below level of detection)

Stem cell cultures are sensitive to endotoxins1, which can be present in media, serum and as a contaminant on plasticware.  We optimise our protein production processes to ensure the lowest possible levels of endotoxin contamination.    Our endotoxin pass criteria are set at the industry leading <0.1 EU per ug protein and we aim for <0.01 EU per ug protein.  Endotoxin levels in our proteins are determined by an external expert microbiological testing services provider.

1. A biological study establishing the endotoxin limit for in vitro proliferation of human mesenchymal stem cells (2017). Yusuke Nomura, Chie Fukui, Yuki Morishita, Yuji Haishima. Regenerative Therapy, 7, 45-51.

View full batch quality testing data for Qk001

Batch #011, #012

Protein is provided in PBS without carrier protein. Protein concentration is 1 mg/ml.

All our proteins are produced in-house by our scientists and we provide detailed quality data for each individual batch.  Please contact us any time by email support@qkine.com or phone +44 (0) 1223 491486 if you have any questions.

After aliquotting the protein, we choose a vial at random and dilute as recommended to ensure we are testing as close to the protein you will receive as possible.  Biochemical identity and purity of each batch is checked using SDS-PAGE, mass spectrometry and analytical reverse phase chromatography.  We use a sensitive test to ensure endotoxin levels are at industry leading low levels (<0.01 EU per µg protein).  We also check that the correct amount of protein is recovered from the vial – it might sound basic but if you order 100 µg, we believe you should receive 100 µg.

View units sizes available and purchasing information online or email orders@qkine.com

Our products are for research use only and not for diagnostic or therapeutic use.  Products are not for resale.