Technote | Activin A (Qk001Qk035)
Qkine follistatin-resistant activin A (FRACTA) and wild type activin A have equivalent bioactivity
Follistatin-resistant activin A (FRACTA) protein has been engineered to prevent binding to the natural inhibitor, follistatin. In vivo activin A activity is regulated by follistatin, a high-affinity inhibitor; follistatin accumulates in stem cell culture, where it inhibits activin A.
Follistatin-resistant activin A (FRACTA, Qk035) has equivalent bioactivity to wild-type activin A (Qk001) but does not bind follistatin so is resistant to feedback inhibition.
Qkine FRACTA vs activin A bioactivity
- Follistatin-resistant activin A (FRACTA) was bioactive with an EC50 of 0.22 ng/ml (8.8 pM).
- This was equivalent to the EC50 for wild-type activin A, 0.23 ng/ml (8.8 pM).
Qkine follistatin-resistant activin A (FRACTA) was as bioactive as wild type activin A. Bioactivity was determined using the activin-responsive firefly luciferase reporter assay in transiently transfected HEK293T cells. Cells were treated in triplicate with a serial dilution of FRACTA (Qk035, green) or wild type activin A (Qk001, black).
Qkine recombinant proteins have the advantage of being highly pure and animal origin-free, giving lot-to-lot consistency in bioactivity for long-term reproducible culture of stem cells and organoids.
All our recombinant proteins are animal-free and come with Bioactivity. Guaranteed.
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