Hu/Ms Recom Activin A, 1000 µg

A lyophilized recombinant protein from STEMCELL Technologies, expressed in E. coli as a disulfide-linked homodimer of two beta-A chains. Belonging to the transforming growth factor beta (TGF-β) family, the protein signals through SMAD2/3 to regulate cellular processes including proliferation, differentiation, wound healing, apoptosis, and metabolism. Activin A is recognized for maintaining the undifferentiated state of human embryonic stem cells and for facilitating their differentiation into definitive endoderm.

The product is lyophilized from a sterile-filtered aqueous solution containing 0.1% trifluoroacetic acid. Reported specifications include a predicted molecular mass of 13.1 kDa for the monomer and 26.2 kDa for the dimer, with purity ≥ 95% and an endotoxin level ≤ 1 EU/µg protein by kinetic LAL analysis. Biological activity is determined by a cell proliferation assay using MPC-11 cells, where the EC50 specification is ≤ 10 ng/mL and the example assay produced an EC50 of 1.9 - 2.9 ng/mL. The specific activity is approximately 1.2 IU/µg as calibrated against the human recombinant Activin A WHO International Standard (NIBSC code: 91/626). Cross-reactivity is reported for human and mouse.

The lyophilized vial should be centrifuged before opening and reconstituted in sterile water to at least 0.1 mg/mL by pipetting the solution down the sides of the vial without vortexing. Unopened material is stored at -20°C to -80°C and is stable as supplied for 12 months from the date of receipt. The product is for research use only.