Recombinant human EGF protein (Qk011)


Recombinant human EGF protein is a 6.3 kDa biologically active domain of human epidermal growth factor. Our recombinant EGF protein is expressed to the highest purity in E. coli and extensively tested, making it ideal for use in chemically-defined iPSC, ESC and organoid culture media. 

Qk011 Recombinant human EGF protein

Human 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 the successful expansion and differentiation of epithelial, neural, mesoderm and hematopoietic lineages.

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

Members of the human epidermal growth factor 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 surface1. The mature form of human EGF protein comprises 53 amino acids2. Epidermal growth factor binds to high-affinity EGF receptors (EGFRs) and promotes receptor dimerization and clustering leading to activation of downstream signalling pathways, including PI3K, ERK1/2, JAK/STAT, β-catenin, and calcium signalling3.

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

Molecular mass: 6.3 kDa

Form: protein is provided lyophilized from a fully volatile solution without carrier protein. Animal-derived component free.

Purity and bioactivity

For peace of mind that our recombinant human EGF protein will work exactly the same way every day, from batch to batch and at any scale you need, we conduct extensive purity and quantitative bioactivity analysis. This includes SDS-PAGE, mass spectrometry, reversed-phase chromatography, UV spectroscopy and endotoxin level testing.

Find out more about our extensive purity testing in the next tab.

Example data

Protein purity: SDS-PAGE in reduced and non-reduced conditions

Recombinant human EGF protein purity in SDS-PAGE

Bioactivity: EGF-responsive SRE luciferase reporter* assay

Bioactivity of recombinant human EGF protein using Promega SRE -reporter luciferase assay
*Promega pGL4.33[luc2P/SRE/Hygro] #E1340

Research applications

Organoid culture

iPSC/ESC differentiation

All our proteins are produced in our Cambridge, UK labs.  We provide detailed quality data for each batch because we believe reliable, high-quality cytokines and growth factors are critical for successful stem cell and organoid culture.  Please contact us with questions any time by email at or phone +44 (0) 1223 491486 / US toll free 1-866 877 2185.

Order online and upload your PO or pay by credit card,  or email your PO to

We provide bulk orders and stock reservation for sensitive applications, please email us.

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

For final purity and activity tests on our proteins, we choose a vial at random and reconstitute as recommended. Biochemical identity and purity is determined using SDS-PAGE, mass spectrometry and analytical reversed-phase chromatography. Bioactivity is quantified using an appropriate cell-based assay. As stem cells are sensitive to endotoxin levels, we use a high resolution 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, so you can rely on your calculated dilution.

Purity: SDS-PAGE

 Recombinant human EGF protein purity in SDS-PAGE

Bioactivity: luciferase reporter assay

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 recombinant human 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 normalized to the control Renilla luciferase activity. Data are from Qk011 batch #011.

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

Purity: mass spec analysis

Purity: analytical reversed-phase chromatography

Purity: endotoxin level determination

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.  Example data from Qk001 batch #011

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.

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Please follow the handling guidance for lyophilized cytokines below to minimize loss of protein due to precipitation or adsorption to plastic. We advise storing our recombinant human EGF protein at very low pH before dilution in cell culture media or your final working solution. Low pH will also assist in maintaining the correct disulfide structure of the protein by minimizing disulfide bond exchange reactions.

  • Resuspension in physiological buffers may cause precipitation of stock solutions, hence we recommend dissolving our lyophilized 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 solubilization 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 store frozen.
  • Our proteins are supplied carrier protein-free. If compatible with your work, add carrier protein of your choice such as BSA, HSA or gelatin to further minimize loss by adsorption.
  • Store in -80°C for long-term storage, -20°C for short-term.

We 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, so when you use the proteins you can rely on your calculated dilution.

Recovery: protein quantitation

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 recombinant human 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.

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