Hu Recom IL-5, ACF, 10 µg

An animal component-free human recombinant Interleukin-5 (IL-5) supplied by STEMCELL Technologies as a lyophilized protein produced in E. coli. IL-5 belongs to the short-chain 4-α-helical bundle subset of hematopoietic cytokines and signals through a receptor composed of IL-5Ra together with the common beta chain that is shared with the IL-3 and GM-CSF receptors. Engagement of this receptor activates the JAK/STAT and MAPK pathways. IL-5 is produced by Th2 cells, eosinophils, and activated mast cells, and it acts on eosinophils to drive their recruitment, activation, proliferation, and survival, contributing to its roles in allergic inflammation, asthma, and parasite immunity. The protein is reported to be species-specific and is also known by alternative names including B-cell differentiation factor I, EDF, Eosinophil colony-stimulating factor, Eosinophil differentiation factor, T-cell replacing factor (TRF), and Interleukin-5 (UniProt accession P05113).

The cytokine has a predicted molecular mass of 13.3 kDa as a monomer and 26.6 kDa as a dimer, with purity of ≥ 95% as resolved by SDS-PAGE under reducing and non-reducing conditions. Endotoxin is ≤ 1 EU/μg protein as determined by kinetic Limulus amebocyte lysate (LAL) analysis. Bioactivity is measured by a cell proliferation assay using TF-1 cells, yielding a specific activity of ≥ 4.0 x 10^6 units/mg with an EC50 of ≤ 0.25 ng/mL; a representative EC50 of 0.166 ng/mL was observed. The product is lyophilized from a sterile-filtered solution of sodium glycinate at pH 8.5.

Before opening, the vial should be centrifuged and the contents reconstituted in sterile water to at least 0.1 mg/mL by pipetting the solution down the sides of the vial; vortexing should be avoided. For storage, the lyophilized product is kept at -20°C to -80°C and is stable as supplied for 12 months from the date of receipt. The product is intended for research use only and is not intended for human or animal diagnostic or therapeutic applications.