| abstract |
Interferon gamma is produced in highly purified form (activity exceeding 108 units/ml-day) by CHO cells cotransformed by a first plasmid bearing the genomic human interferon gene under the control of the SV40 early promoter, and a second plasmid bearing a DHFR gene under similar control. Methotrexate selection yielded a clone which was a particularly efficient producer. Production of interferon gamma may also be facilitated by a Harvey sarcoma virus enhancer sequence. |