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-origin free and carrier protein-free growth factors and cytokines for stem cell maintenance.
Growth factors for iPSC and ESC maintenance media
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
Growth factors for organoid culture media
StemPro media
Recombinant human activin A protein (Qk001) Recombinant human FGF-2 (145 aa) protein (Qk025) Recombinant human FGF-2 (154 aa) protein (Qk027) Recombinant zebrafish FGF-2 protein (Qk002) Recombinant human IGF-1 protein (Qk047) Recombinant human IGF-1 LR3 protein (Qk041) Recombinant human NRG-1 protein (Qk045) Recombinant human TGF-β1 PLUS™ protein (Qk010) Recombinant human TGF-β3 protein (Qk054)
B8 media
Recombinant human FGF-2 (145 aa) protein (Qk025) Recombinant human FGF-2 (154 aa) protein (Qk027) Recombinant zebrafish FGF-2 protein (Qk002) Recombinant FGF2-G3 (145 aa) protein (Qk052) Recombinant FGF2-G3 (154 aa) protein (Qk053) Recombinant human IGF-1 protein (Qk047) Recombinant human IGF-1 LR3 protein (Qk041) Recombinant human NRG-1 protein (Qk045) Recombinant human TGF-β1 PLUS™ protein (Qk010) Recombinant human TGF-β3 protein (Qk054)Qkine animal origin-free TGF-β1 PLUS™ enhances pluripotency maintenance
Qkine TGF-β1 PLUS™ protein is the first entirely animal origin-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 optimized mature domain of TGF-β1 protein, animal origin-free (AOF) 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 origin-free TGF–β1,2 and 3 proteins for improved cell culture media development.
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 (Supplier 1, EC50 = 3.5 pM and Supplier 2, EC50 = 38 pM.)
Composition of 4 of the most commonly used human pluripotency media
| Components | Recipe | |
|---|---|---|
| mTeSR1 | DMEM/F12, BSA, FGF-2, TGF-β1, insulin, transferrin, cholesterol, lipids, pipecolic acid, GABA, b-mercaptoethanol | Ludwig et al 2006 [2] |
| E8 | DMEM/F12, FGF-2, TGF-β1, insulin, transferrin, selenium, ascorbic acid | Beers et al 2012 [3] |
| B8 | DMEM/F12, FGF2-G3 (FGF2-STAB®), TGF-β3/TGF-β1, NRG-1 (Heregulin-β1), insulin/IGF-1 LR3, ascorbic acid, transferrin, sodium selenite, sodium bicarbonate | Lyra-Leite et al 2021 [4] |
| StemPro | DMEM/F12, BSA, FGF-2, TGF-β1, activin A, IGF-1 LR3, NRG-1 (Heregulin-β1), transferrin, | Wang et al 2007 [5] |
Animal origin-free growth factors and cytokines for stem cell maintenance
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