Abstract: A process for the preparation and purification of recombinant Interferon-.alpha. is disclosed. The invention is directed to a process comprising the following steps: cultivating E. coli containing the interferon gene for a growth period during which not more than 5% methionine-interferon is formed; extracting and concentrating the expressed interferon; subjecting the preliminarily purified material to Tandem Chromatography, wherein the Tandem Chromatography comprises separation on a cellulose column followed by an anti-alpha-interferon monoclonal antibody affinity column; subjecting the thus purified material to isoelectric precipitation of impurities at about pH 4.0 to about pH 4.8; and purifying the interferon by chromatography on a high performance cation exchange column using a volatile buffer, wherein the purified interferon is non-immunogenic when administered parenterally to a human.

Abstract: This invention relates to a DNA molecule or a functional derivative thereof coding for a fusion protein, the fusion protein comprising an enzymatically active component and a non-enzymatically active polypeptide component which may be cleaved therefrom, an expression system which contains the DNA molecule, the use thereof as a test system for inhibitors of viral proteases, and an assay for identifying viral inhibitors.

Abstract: This invention relates to new hybrid interferons consisting of part of an .alpha.-interferon and part of an omega interferon, the N-terminal Met or N-formyl-Met derivatives thereof and, if the peptide sequence of the hybrid interferon contains a glycosylation site, the N-glycosylated derivatives thereof, their use as pharmaceutical compositions and as intermediate products for immunizing experimental animals and processes for producing them,new monoclonal antibodies and their use in purifying .alpha. and omega-interferons, the hybrid cell lines which secrete them and processes for preparing them,a new process for purifying .alpha. and omega-interferons by means of a new antibody affinity column containing the above-mentioned new monoclonal antibodies, and processes for the preparation thereof,new hybrid plasmids for improving the expression of omega-interferons and new intermediate plasmids for preparing the new plasmids and processes for the preparation thereof.