A novel concept in the purification of human leukocyte interferon.

A method for the purification of natural human interferon alpha (HuIFN Alpha) is described. It involves adsorption of interferon on silicic acid and its elution with hydrophobic electrolyte solution. Thereafter, elimination of possible viruses is achieved using nonionic detergent and ultrafiltration. Interferon recovered in the ultrafiltrate is further purified on Sephacryl S-200. Fractions corresponding to molecular weights ranging from approximately 10,000 to approximately 40,000 daltons are collected and directly applied on immobilized zinc affinity gel. IFN Alpha which is eluted with the non adsorbed fraction is subjected to buffer exchange, concentration, and sterilization. The resulting solution shows high specific activity (1 x 10(7) IU) with an apparently natural composition of interferon isospecies. The uniform buffer employed through the entire purification process makes it simple, fast and reproducible.