Recombinant human EGF protein (Qk011)2020-01-30T12:36:18+00:00

Recombinant human EGF protein (Qk011)

Epidermal growth factor (EGF) stimulates cell proliferation and differentiation. It is used extensively in induced-pluripotent stem cell (iPSC) and embryonic stem cell (ESC) culture systems for successful expansion and differentiation of epithelial, neural, mesoderm and hematopoietic lineages.

EGF is a key component of many organoid media and, along with other stem cell niche factors, R-spondin 1, Noggin or Gremlin, Wnt3a and FGF10, and is used for establishing and maintaining intestine, stomach, liver, pancreas, brain and cancer organoids.

Members of the EGF family are synthesized as type I transmembrane precursor proteins, often containing several EGF domains in the extracellular region. Proteolysis yields mature proteins that are released from the cell surface (1). The mature form of human EGF comprises 53 amino acids (2). EGF binds to high affinity EGF receptors (EGFRs) and promotes receptor dimerization and clustering leading to activation of down-stream signalling pathways including PI3K, ERK1/2, JAK/STAT, β-catenin, and calcium signalling (3).

Summary: Qk011 mature domain of human EGF (residues 971-1023, Uniprot: P01133) expressed in E.coli and purified to homogeneity

Molecular mass: 6.3 kDa

Form: protein is provided lyophilised from a fully volatile solution without carrier protein.

Please follow the handling guidance for lyophilised cytokines below to minimise loss of protein due to precipitation or adsorption to plastic.  We advise storing the recombinant protein at very low pH to before dilution in cell culture media or final working solutions. Low pH will also assist in maintaining the correct disulphide structure of the protein by minimising disulphide bond exchange reactions.

  • Resuspension in physiological buffers may cause precipitation of stock solutions, hence we recommend dissolving our lyophilised cytokines in 10 mM HCl (1:1000 dilution of concentrated HCl) while keeping the protein concentration at 50 µg/ml or above, in order to avoid loss by adsorption to plasticware.
  • To ensure you recover all of the protein, let the sample sit for a few minutes with the solubilisation buffer at room temperature and pipette gently up and down (avoid foaming).
  • Rinse the tube with some more 10 mM HCl and pool with the rest.
  • The protein is tolerant of some freeze and thaw cycles, but as always with proteins, it is better to aliquot and stored frozen.
  • 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.
  • Store in -80°C for long term storage. -20°C for short-term.

1. Harris, R. C., Chung, E. & Coffey, R. J. EGF receptor ligands. Experimental cell research 284, 2–13 (2003).
2. Bell, G. I. et al. Human epidermal growth factor precursor: cDNA sequence, expression in vitro and gene organization. Nucleic acids research 14, 8427–8446 (1986).
3. Carpenter, G. & Cohen, S. Epidermal growth factor. The Journal of biological chemistry 265, 7709–7712 (1990).

Epidermal growth factor, Pro-epidermal growth factor, HOMG4, Beta-urogastrone, Urogastrone (URG)

Result: EGF migrates as major band at 6.3 kDa in non-reducing (-βME) conditions and upon reduction (+βME).

 Recombinant EGF protein purity in SDS-PAGE

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: EGF activity is determined using the Promega serum response element luciferase reporter assay (*) in transfected HEK293T cells. EC50 = 29 pg/ml (4.6pM)

Bioactivity of EGF protein using Promega SRE -reporter luciferase assay

Cells are treated (n=2) with a serial dilution of EGF for 3 hours. Firefly luciferase activity is measured and normalised to the control Renilla luciferase activity. Data are from Qk011 batch #011.

*Promega pGL4.33[luc2P/SRE/Hygro] #E1340

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

Absorbance at 280 nm: average 0.29
Recovered concentration: 0.295 cm-1 x 10 / 2.9 cm-1 mg ml-1 =  mg / ml
Recovery: 99%

 Check full recovery from vial of EGF protein using UV spectrum

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 optimize 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.

All our proteins are produced in our Cambridge, UK, facility by our scientists.  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 USA toll free 1-866 877 2185 if you have any questions.

Order online by clicking below or email orders@qkine.com

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

  • Epidermal growth factor (EGF) recombinant protein for induced-pluripotent stem cell (iPSC), embryonic stem cell (ESC) and organoid culture.  For successful expansion and differentiation of epithelial, neural, mesoderm and hematopoietic lineages.  Use along with other stem cell niche factors, R-spondin 1, Noggin or Gremlin, Wnt3a and FGF10, in defined and animal-derived component free media for establishing and maintaining intestine, stomach, liver, pancreas, brain and cancer organoids.