IFN-alpha is produced by macrophages and has antiviral activities. IFN stimulates the production of two enzymes: protein kinase and an oligoadenylate synthetase. IFN-a 2b Human Recombinant produced in E.Coli is a single, non-glycosylated, polypeptide chain containing 166 amino acids and having a molecular mass of 19400 Dalton. The difference between IFNA2A and IFNA2B is in the amino acid present at position 23. IFN-alpha 2a has a lysine at that position 23 while IFN-alpha 2b has arginine. The IFN-alpha 2b gene was obtained from human leukocytes.