Growth factors and cytokines for stem cell maintenance

Qkine is committed to manufacturing enhanced-quality bioactive proteins to improve scientific outcomes and reproducibility. We provide a complete portfolio of animal-free and carrier protein-free growth factors and cytokines for stem cell maintenance.

Maintenance of pluripotency in human iPSC and ESC

Several standard-defined media have been adopted for human stem cell maintenance, including mTESR, E8 and StemPro. Most recently, weekend-free media B8, developed by Paul Burridge at Northwestern University, utilises thermostable (heat-stable) FGF-2 (FGF2-G3) developed by Dvorak and colleagues at Masaryk University and Enantis Ltd.

In the search for conditions that maintain pluripotency in human pluripotency stem cells, several media formulations have been described (the composition of most popular of which is shown in table 1), in general each of which targets 3 main signalling pathways. [1]

Activation of the PI3K/AKT/mTOR and MAPK/ERK pathways by FGF-2 and/or neuregulin 1 (NRG-1), which bind FGFR1/FGFR4 or ERBB3/ERBB4

Activation of the TGF-β signaling pathway by TGF-β1, nodal, or activin A, which bind TGFBR1/2 and/or ACVR2A/2B/1B/1C (nodal is used less commonly in pluripotent medium formulations due to the expression of the nodal antagonists LEFTY1/2 in hPSCs)

Activation of the PI3K/AKT pathway, promoting cell survival and growth, by insulin or insulin growth factor (IGF-1), which binds INSR and IGF1R

All our recombinant proteins are animal-free
and come with Bioactivity. Guaranteed.

Learn more

Qkine animal-free TGF beta 1 PLUS enhances pluripotency maintenance

Qkine TGF B1 Plus bioactivity graph comparison

Quantitative luciferase reporter assays show TGF-β1 PLUS (Qk010, green) has higher bioactivity (EC50=1.4 pM for lot #011 and #012) when compared with mammalian expressed TGF-β1 from two alternative suppliers (blue, Supplier 1 EC50=3.5 pM, Supplier 2 EC50=38 pM.)

Human/bovine/porcine TGF-β1 PLUS protein is the first entirely animal-free recombinant human transforming growth factor beta 1 (TGF-β1) protein for highly reproducible results and compatible with chemically-defined stem cell media. TGF-β1 is used extensively in E8-style induced pluripotent (iPSC) and embryonic (ESC) stem cell media.

High purity 24 kDa dimer comprising optimised mature domain of TGF-β1 protein, animal-free (AF) and carrier-protein free (CF). Our TGF-β1 PLUS protein has been extensively tested for maintenance of iPSC pluripotency by the specialist stem cell biotechnology company, Stemnovate, Cambridge, UK

Our TGF-β1 PLUS is part of our TGF beta family which comprises of the first quality-matched animal-free TGF–β 1,2 and 3 proteins for improved cell culture media development.

Buy TGF-β1 PLUS

TGF beta family technote

Table 1. The composition of 4 of the most popular human pluripotency media

	Components	Recipe
mTeSR1	DMEM/F12, BSA, FGF2, TGFβ1, insulin, transferrin, cholesterol, lipids, pipecolic acid, GABA, b-mercaptoethanol	Ludwig et al 2006²
E8	DMEM/F12, FGF2, TGFβ1, insulin, transferrin, selenium, ascorbic acid	Beers et al 2012³
B8	DMEM/F12, FGF2-G3 (FGF2-STAB®), TGFβ3/TGFβ1, NRG1 (Heregulin-β1), insulin/IGF1 LR3, ascorbic acid, transferrin, sodium selenite, sodium bicarbonate	Lyra-Leite et al 2021⁴
StemPro	DMEM/F12, BSA, FGF2, TGFβ1, Activin A, IGF-1 LR3, NRG1 (Heregulin-β1), transferrin,	Wang et al 2007⁵

References

Kuo, Hui-Hsuan, et al. ‘Negligible-Cost and Weekend-Free Chemically Defined Human IPSC Culture’. Stem Cell Reports, vol. 14, no. 2, Feb. 2020, pp. 256–70.
Ludwig, Tenneille E., et al. ‘Feeder-Independent Culture of Human Embryonic Stem Cells’. Nature Methods, vol. 3, no. 8, Aug. 2006, pp. 637–46.
Beers, Jeanette, et al. ‘Passaging and Colony Expansion of Human Pluripotent Stem Cells by Enzyme-Free Dissociation in Chemically Defined Culture Conditions’. Nature Protocols, vol. 7, no. 11, 2012, pp. 2029–40.
Lyra-Leite, Davi Marco, et al. ‘An Updated Protocol for the Cost-Effective and Weekend-Free Culture of Human Induced Pluripotent Stem Cells’. STAR Protocols, vol. 2, no. 1, Mar. 2021, p. 100213.
Wang, Linlin, et al. ‘Self-Renewal of Human Embryonic Stem Cells Requires Insulin-like Growth Factor-1 Receptor and ERBB2 Receptor Signaling’. Blood, vol. 110, no. 12, Dec. 2007, pp. 4111–19.
Chen, Chen-Yun, et al. ‘Mechanisms of Pluripotency Maintenance in Mouse Embryonic Stem Cells’. Cellular and Molecular Life Sciences, vol. 74, no. 10, May 2017, pp. 1805–17.
Merrill, B. J. ‘Wnt Pathway Regulation of Embryonic Stem Cell Self-Renewal’. Cold Spring Harbor Perspectives in Biology, vol. 4, no. 9, Sept. 2012, pp. a007971–a007971.

Featured resources for stem cell maintenance

iPSC maintenance protocol

Weekly schedule for routine maintenance of iPSC

This protocol describes a method for maintaining the pluripotency of iPSCs without the need for daily feeding, enabling weekend-free maintenance and expansion.

Learn more

TGF-beta family technote