Interleukin-2 Human Recombinant produced in E.Coli is a single, non-glycosylated, Polypeptide chain containing 133 amino acids fragment (21-153) having a molecular weight of 20kDa and fused with a 4.5kDa amino-terminal hexahistidine tag. The IL-2 His is purified by proprietary chromatographic techniques.