Technote | Activin A (Qk001Qk001-CTG)
Reconstituted activin A protein has excellent stability under standard storage conditions
Activin A is frequently used to maintain pluripotency in induced pluripotent and embryonic stem cell cultures. It is also used in many stem cell differentiation protocols, including endoderm lineage differentiation and further maturation into hepatocyte and pancreatic cells.
Qkine activin A (Qk001) is a high-purity mature bioactive dimer which is animal origin-free, carrier protein-free and tag-free.
Qkine activin A one month stability
- Activin A diluted to 50 µg/ml and stored in PBS + 0.1% BSA at -20 °C for one month had an EC50 of 0.36 ng/ml, equivalent to freshly reconstituted protein stored lyophilized at -80 °C, which had an EC50 of 0.26 ng/ml.
- When the 50 µg/ml activin A in PBS + 0.1% BSA was stored at 4 °C for one month it had an EC50 of 0.32 ng/ml, equivalent to the freshly reconstituted protein, which had an EC50 of 0.28 ng/ml.
- When diluted further to 1 µg/ml in cell culture medium and stored at 4 °C for one month activin A retained an EC50 of 0.56 ng/ml, equivalent to freshly reconstituted protein, which had an EC50 of 0.42 ng/ml.
Activin A remained bioactive under all tested storage conditions. Bioactivity was determined using a CAGA reporter luciferase assay; transfected HEK293T cells were treated in triplicate with a serial dilution of activin A (Qk001) which had been reconstituted and stored for one month under the conditions indicated. Firefly luciferase activity was measured and normalized to control Renilla luciferase activity. (A) Bioactivity of control activin A (freshly reconstituted and diluted from protein stored lyophilized at -80 °C) compared with protein stored in PBS + 0.1% BSA at -20 °C for one month. (B) Bioactivity of a control protein compared with protein stored in PBS + 0.1% BSA at 4 °C for one month. (C) Bioactivity of control protein compared with protein stored in cell culture medium at 4 °C for one month.
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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