Thermostable FGF 2 G3 for iPSC stem cell media
FGF2-G3 (Qk053)
FGF2-G3 145aa (Qk052)

why FGF2-G3 (FGF2-STAB®)?

FGF 2 is essential in stem cell media but inherently unstable

  • FGF 2 is prone to proteolytic degradation and aggregation in solution and in media
  • in culture, the half-life of FGF 2 is <10 hours, with reports as low as 40 minutes
  • this contributes to the need for frequent media changes and challenges in improving homogeneity during stem cell proliferation and subsequent differentiation

FGF2-G3 is a hyperstable form of FGF 2 with the same bioactivity

  • FGF2-G3 contains an optimal set of nine amino acid substitutions that stabilize FGF 2 without affecting FGF receptor binding
  • functional half-life in culture is increased to >20 days

enables highly homogeneous iPSC and hESC culture

  • core ingredient in B8 weekend-free media
  • facilitates optimisation of protocols for homogeneous iPSC culture and efficient differentiation
read the history of FGF2 and stem cell culture

why Qkine FGF2-G3

compare directly with your existing FGF 2

For the first time, a 145 aa FGF-G3 (Qk052) is also available so you can compare directly with your existing FGF 2.

no His tag here!

We don’t like His tags. They increase contaminants, introduce scientific uncertainty and lead to issues when scaling or translating discoveries.

high purity and animal-free

All our proteins are animal-free with extensive biochemical and bioactivity data for every lot. Manufactured in our ISO9001: 2015 certified facility.

FGF2-G3 uses

In the quest for homogeneous, undifferentiated stem cells, and highly controlled reproducible differentiation, the stability of signalling provided by FGF2-G3 is an attractive alternative to standard FGF 2. The first media developed using FGF2-G3 to gain traction is B8 media, from the lab of Paul Burridge, Northwestern University.

  • used for homogeneous iPSC and ESC culture
  • designed to be cost-effective
  • allows weekend-free pluripotent stem cell culture
  • every component comprehensively reviewed and optimized
  • FGF2-G3 is an essential ingredient in B8 media (replacing standard FGF2)
  • animal-free TGFB1 PLUS (Qk010) and NRG1 (Qk045) also available for fully animal-free B8 media

stable at 37oC

Fresh from the freezer, FGF2 (Qk027) and FGF2-G3 (Qk053) have equivalent bioactivity (0 hours). FGF2-G3 retains this activity after storage in conditioned media at 37oC (24, 48 and 72 hours).

FGF2-G3 (Qk053)             FGF2 (Qk027)

0 hours
24 hours
48 hours
72 hours

FGF2-G3 activity is determined using the Promega serum response element luciferase reporter assay (*) in transfected HEK293T cells.
Cells are treated in triplicate with a serial dilution of FGF2-G3 for 3 hours. Firefly luciferase activity is measured and normalized to the control Renilla luciferase activity.
*Promega pGL4.33[luc2P/SRE/Hygro] #E1340

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FGF2-G3 (Qk053)
FGF2-G3 145aa (Qk052)

Qkine manufacture

support and information about protein manufacture, quality and ordering

  • animal-free

    Unmatched quality and reliability. All our proteins are made in a dedicated animal-free laboratory in Cambridge, UK.

  • total transparency

    Know what you’re giving your cells. Stringent purity and bioactivity data for all proteins.

  • protein innovation

    Solving stem cell culture challenges with optimised forms and animal-free firsts.

key papers

Dvorak et al. 2018

development of FGF2-G3 form using AI

Koledova et al. 2019

assessment of FGF2-G3 stability and signalling

Kuo et al. 2020

development of B8 media – low cost, weekend free iPSC media

Lyra-Leite et al. 2021

updated protocol for B8 media

Benington et al. 2020

nice review of FGF2 stability and stabilisation methods

tunable growth factors – the future of scalable stem cell culture