IL-9 produced in Sf9 Baculovirus cells is a single, glycosylated polypeptide chain (19-144 a.a.) including an 18 aa signal peptide (1-18 aa) and fused to a 6 aa His Tag at C-terminus containing a total of 150 amino acids and having a molecular mass of 14.5kDa. IL9 shows multiple bands between 18-28kDa on SDS-PAGE, reducing conditions and purified by proprietary chromatographic techniques. Purity >90.0% as determined by SDS-PAGE.