Hu Recom IL-21, ACF, 1000 µg

Manufactured by STEMCELL Technologies as a 1000 µg lyophilized vial of E. coli-derived human Interleukin-21, this animal component-free (ACF) preparation is intended for in vitro research applications spanning NK cell expansion, plasma cell differentiation, and CAR-T co-culture protocols. The recombinant cytokine has a predicted molecular mass of 15.4 kDa and is purified to ≥ 97% as assessed by SDS-PAGE under reducing and non-reducing conditions, visualized by Coomassie Blue staining.

Biological activity is verified by a B9 cell proliferation assay, with a specific activity of ≥ 2 x 10^5 units/mg and an EC50 ≤ 5 ng/mL. Endotoxin content is held to ≤ 0.1 EU/µg by kinetic LAL analysis, supporting use in sensitive primary immune cell culture and defined xeno-free workflows. The lyophilized product is supplied in sodium phosphate buffer at pH 7.5 and is reconstituted in sterile, low-endotoxin water or PBS. For storage, the unreconstituted vial is kept at -20 °C or colder, with single-use aliquots recommended to limit freeze-thaw cycles.

Alternative nomenclature: Interleukin-21, Za11 (UniProt accession Q9HBE4). Researchers requiring documentation of animal-component-free upstream manufacturing for translational cell-therapy pipelines will find the lot-traceable ACF certification useful when scaling cultures toward clinical-grade conditions.