IL5 Human, Sf9

Recombinant human IL-5 is produced using the Sf9 Baculovirus expression system. The Sf9 cell line is derived from the fall armyworm, Spodoptera frugiperda. This system is widely used for the production of recombinant proteins due to its ability to perform complex post-translational modifications .

The recombinant IL-5 produced in Sf9 cells is a single, glycosylated polypeptide chain containing 124 amino acids, with a molecular mass of approximately 14.2 kDa. The protein is expressed with a 6-amino acid His-tag at the C-terminus, which aids in its purification . The molecular size on SDS-PAGE appears at approximately 13.5-18 kDa .

IL-5 acts as a growth and differentiation factor for both B cells and eosinophils. It is a main regulator of eosinopoiesis, eosinophil maturation, and activation. The elevated production of IL-5 is associated with conditions such as asthma and hypereosinophilic syndromes . The biological activity of recombinant IL-5 is measured in a cell proliferation assay using TF-1 human erythroleukemic cells, with an effective dose (ED50) of less than or equal to 1.5 ng/mL .

Recombinant IL-5 is typically supplied as a sterile filtered colorless solution in phosphate-buffered saline (PBS) with 10% glycerol. For long-term storage, it is recommended to store the protein at -20°C, and for short-term use, it can be stored at 4°C for 2-4 weeks. It is important to avoid multiple freeze-thaw cycles to maintain the protein’s stability .

Recombinant IL-5 is used in various research applications, including studies on eosinophil biology, asthma, and other allergic diseases. It is also used in cell culture and as a standard in enzyme-linked immunosorbent assays (ELISAs).