Recombinant FGF2-G3 (145 aa) protein (Qk052) Price range: £175.00 through £880.00View product
Recombinant FGF2-G3 (145 aa) protein (Qk052)
Price range: £175.00 through £880.00
FGF2-G3 (145 aa) protein is a thermostable engineered form of FGF-2 (bFGF). Qk052 comprises the 145 aa form of FGF-2 (Qk025) with the nine amino acid substitutions developed by Dvorak et al. 2018. This increases the functional half-life of the protein from <10 h (wild-type) to >7 days (FGF2-G3 145 aa).
FGF2-G3 is used in B8 media (Kuo et al. 2019) for weekend free, high homogeneity induced pluripotent stem cell culture. This new 145 aa thermostable FGF-2 protein allows direct comparison of efficacy in systems using FGF-2 145 aa (Qk025) for chemically defined stem cell and organoid culture media, and cultured meat media development. High purity 16 kDa bioactive FGF2-G3 145 aa protein, animal origin-free (AOF), carrier protein-free and with no His-tag.
Product manufactured under license: International Patent Application No. PCT/EP2016/073567 and U.S. Patent No. 11,746,135.
This protein is also available as GMP compliant Cell Therapy Grade, to enquire email ryan.weber@matriqx.com.
In stock
Orders are typically shipped same or next day (except Friday).
Easy world-wide ordering, direct or through our distributors.
Price range: £175.00 through £880.00
1000 µg will be dispatched as 2 x 500 µg.
Buy online with secure credit card or purchase order. For any questions, please email ryan.weber@matriqx.com
Summary:
- High purity thermostable FGF2-G3 protein comprising 145 aa form of FGF-2 (Uniprot: P09038) with nine stabilizing amino acid substitutions
- 16 kDa
>98%, by SDS-PAGE quantitative densitometry
Expressed in E. coli
Animal origin-free (AOF) and carrier protein-free
Manufactured in our Cambridge, UK laboratories
Lyophilized from Tris, NaCl, CyS, mannitol
- Resuspend in sterile-filtered water at >50 µg/ml, add carrier protein if desired, prepare single use aliquots and store frozen at -20 °C (short-term) or -80 °C (long-term).
Featured applications:
Induced pluripotent stem cell culture and maintenance
Frequently used together
- Recombinant human VEGF 165 protein (Qk048)
- Recombinant bovine HGF NK1 protein (Qk060)
- Recombinant human FGF-19 protein (Qk086)
- Recombinant human TGF-β2 protein (Qk072)
- Recombinant human activin A PLUS™ protein (Qk005)
- Astrocyte differentiation kit (Qk520)
- QkPlate© human vitronectin coated 6 well plate (Qk2001)
Related discovery kits
Alternative proteins
- Recombinant human FGF-2 (145 aa) protein (Qk025)
- Recombinant FGF2-G3 (154 aa) protein (Qk053)
- Recombinant zebrafish FGF-2 protein (Qk002)
- Microglial differentiation kit (Qk519)
- Food grade thermostable FGF-2 discovery kit (Qk502-FG)
- B8 media discovery kit (Qk503)
- iPSC culture kit (Qk512)
- Mesoderm differentiation kit (Qk514)
- Astrocyte differentiation kit (Qk520)
FGF2-G3 (145 aa) activity was determined using the Promega serum response element luciferase reporter assay in transfected HEK293T cells. Cells were treated in triplicate with a serial dilution of FGF2-G3 (145 aa) for 3 hours. Firefly luciferase activity was measured and normalized to the control Renilla luciferase activity. Data from Qk052 lot #204567. EC50 = 0.38 ng/ml.
FGF2-G3 (145 aa) migrates as a major band at 16 kDa in non-reducing (NR) conditions. A small amount of dimer can be seen (higher molecular weight band). Upon reduction (R), only the 16 kDa band is visible. No contaminating protein bands are present. Purified recombinant protein (3 µg) was resolved using 15% w/v SDS-PAGE in reduced (+β-mercaptothanol, R) and non-reduced (NR) conditions and stained with Coomassie Brilliant Blue R250. Data from Qk052 batch #104339.
Further quality assays
Mass spectrometry: single species with expected mass
Recovery from stock vial: >95%
Endotoxin: <0.05 EU/μg protein
We are a company founded and run by scientists to provide a service and support innovation in stem cell biology and regenerative medicine. All our products are exceptionally high purity, with complete characterisation and bioactivity analysis on every lot.
Thermostable FGF2-G3 145 aa maintains bioactivity for >7 days under cell culture conditions. Bioactivity was determined using the Promega serum response element luciferase reporter assay in transfected HEK293T cells. FGF2-G3 145 aa or WT FGF-2 154 aa (Qk027) were incubated in media at 37°C for 0, 2 or 7 days then cells were treated in triplicate with a serial dilution for 3 hours. Firefly luciferase activity was measured and normalized to the control Renilla luciferase activity.
Protein background
FGF-2 (also known as basic FGF or bFGF) is an essential growth factor for maintaining human embryonic stem cell (hESC) and induced pluripotency stem cell (iPSC) pluripotency in feeder-free and chemically defined stem cell media. It is a core component of widely adopted media including mTESR [1, 2], StemPRO [3] and E8 [4]. However, FGF-2 is inherently unstable and prone to proteolytic degradation and aggregation. This fundamental biochemical instability, and therefore low half-life in culture media (<10 h), is an important contribution to the need for frequent media changes and challenges in improving homogeneity during stem cell proliferation and subsequent differentiation.
To improve the stability of FGF-2 for stem cell media and regenerative medicine applications, Dvorak and colleagues at Masaryk University used computer-assisted protein engineering to identify an optimal set of nine amino acid substitutions that stabilize FGF-2. These substitutions were designed to avoid structural changes to the FGF receptor 1 (FGFR1) and FGF receptor 2 (FGFR2) binding sites. This thermostable FGF-2 is known as FGF2-G3, or FGF2-STAB® [5]. The biological activity of wild-type FGF-2 is <50% after 10h incubation with conditioned media. In contrast, no reduction in FGF2-G3 biological activity is observed after >7 days incubation with conditioned media at 37oC. Both FGF2-G3 and wild-type FGF-2 maintain hESC pluripotency and expression of pluripotency markers Oct-4 and nanog with equivalent efficacy [5].
In 2020, Paul Burridge and colleagues at Northwestern University, Chicago, published a protocol for B8 media. This iPSC maintenance media uses thermostable FGF2-G3, along with optimization of media component concentration and composition to reduce media cost and facilitate weekend-free stem cell culture regimes [6, 7].
To manufacture and provide FGF2-G3 for stem cell culture, including use in B8 media and emerging applications such as cultured meat, Qkine has licensed the patented FGF2-G3 technology from Enantis/Masaryk University. We have combined the excellent science behind the FGF2-G3 technology with our protein manufacture expertise to provide gold standard protein for use in cell culture media. We have removed His tags present in academic forms of the protein, as these may give rise to issues for scientists translating discoveries to the clinical or scale-up. His tags also introduce unnecessary scientific uncertainty.
Additional resources
- Differentiation of induced pluripotent stem cells (iPSCs) into neuroectoderm (PDF)
- Differentiation of induced pluripotent stem cells (iPSCs) into mesoderm (PDF)
- CytoBoost™ for increased proliferation of muscle and fat cells in serum-free cultures (PDF)
- Differentiation of induced pluripotent stem cells (iPSCs) into microglia (PDF)
- Commercial versus in-house media: A comparative study of human induced pluripotent stem cell maintenance (PDF)
- Differentiation of induced pluripotent stem cells (iPSCs) into astrocytes (PDF)
- Enabling robust iPSC maintenance with pre-prepared dried vitronectin-coated plates (PDF)
- Brochure: FGF2-G3 Thermostable FGF-2 for enhanced stem cell culture
- Brochure: Growth factors for neural and glial cell differentiation
- Brochure: Growth factors for enhanced organoid culture protocols
Publications using Recombinant FGF2-G3 (145 aa) protein (Qk052)
-
Refined and benchmarked homemade media for cost-effective, weekend-free human pluripotent stem cell culture
Truszkowski L, Bottini S, Bianchi S et al.
DOI: doi.org/10.12688/openreseurope.18245.2 -
Simplified In Vitro Generation of Human Gastruloids for Modelling Early Development
Azami T, Patton EE and Nichols J.
DOI: doi.org/10.1101/2025.10.15.682610 -
Single Cell Transcriptional Perturbome in Pluripotent Stem Cell Models
Balmas E, Ratto ML, Snijders KE et al.
DOI: http://dx.doi.org/10.2139/ssrn.4854180 -
Animal proteins from stem cells as an alternative to reduce the ecological and climate impact of animal farming
Bottini S (Thesis)
DOI: Thesis
FAQ
What is FGF-2?
Fibroblast growth factor 2 (FGF-2), also known as basic fibroblast growth factor (bFGF) is a growth factor and signaling protein.
Where is FGF-2 found?
FGF-2 is expressed in a developmental and tissue specific manner. It’s expression is tightly controlled in normal tissues and it can be detected in all major tissues.
What does FGF-2 do?
FGF-2 is essential for normal embryonic development. It has roles in cell survival and proliferation, angiogenesis, tumorigenesis, wound healing and tissue repair.
What does FGF-2 bind to?
FGF-2 binds to and signals though all four of the FGF receptors FGFR1-4.
What is the function of the FGF receptor?
FGFRs phosphorylate specific tyrosine residues and activate the RAS-MAPK, PI3K-AKT, PLCγ, and STAT intracellular signaling pathways.
How is FGF-2 used in stem cell culture?
FGF-2 is used to maintain the pluripotency of stem cells in culture.
Why is our truncated FGF-2 145 amino acids rather than 146 amino acids?
We offer the 145 amino acid form rather than the 146 due to the E. coli processing of the N-terminal. When the 146 form (Pro143-Ser288) is expressed, the proline is either partially or completely removed. To improve expression in E. coli, we chose to start with the alanine (Ala144-Ser288) form. This modification does not affect receptor binding or bioactivity.
Other listings of the 146 amino acid form will often be a mixture of FGF-2 146 and 145, or, in some cases, only the 145 form.
What is the difference between FGF-2 145 aa and 154 aa?
Fibroblast Growth Factor 2 (FGF-2) exists in two main isoforms, distinguished by length: 145 amino acids (aa) and 154 aa. The 154 aa variant contains an additional nine amino acids at the N-terminus. While this extension is not essential for biological activity, it may influence the protein’s localization within cells.
Key differences between the isoforms:
-
FGF-2 (145 aa):
-
The most widely used form, supporting proliferation and survival of stem and progenitor cells.
-
Commonly preferred for organoid culture due to its robust activity and well-established performance.
-
-
FGF-2 (154 aa):
-
Contains an N-terminal extension that may affect intracellular localization or signaling.
-
Typically, not required for standard organoid or stem cell maintenance, unless specific signaling or localization effects are being investigated.
-
What is FGF2-G3 (FGF2-STAB®)?
Recombinant FGF2-G3 (FGF2-STAB®) is a thermostable, engineered form of FGF-2 (bFGF). This modification significantly increases the protein’s functional half-life — from <10 hours for wild-type FGF-2 to >7 days for FGF2-G3 — improving stability and consistency in culture systems.
Our products are for research use only and not for diagnostic or therapeutic use. Products are not for resale.
For use in manufacturing of cellular or gene therapy products. Not intended for in vivo applications.
Receive a Qkine gift card when you leave us a review.
£100, $140 or €120 Qkine gift card for product reviews with an image and £50, $70 or €60 for reviews without an image.